MIT Wristband Could Make Air Conditioning Obsolete | Hacker News Reader

MIT Wristband Could Make Air Conditioning Obsolete

wired.com

295 pointspetercooper132 comments

I live in a small "flat" in India. Without A/C in the summer (only at night), our consumption is ~200 KWhr per month. With A/C only in one room for something like 4-5 hours per day, it shoots up to ~500 KWhr per month. Indians switching to A/C on a big scale will be a disaster for the world.

I believe that the answer lies in architecture, not in more energy-intensive devices which may or may not actually work (this one fools the body - that could be catastrophic, increasing chances for a heat stroke). India was always hot - but older buildings used to be built (1) with high ceilings (2) with cross-ventilation.

http://www.architecture.com/SustainabilityHub/Designstrategi...

This contrasts with buildings in cold countries, where buildings are insulated against winter. In the name of "better" buildings, Indians are switching to sealed buildings working with Central A/C. Blind imitation.

On the other hand, there were builders committed to "environment-friendly", low cost buildings (not the modern scam of "green buildings", which are actually more expensive.) Laurie Baker in South India was one - a real unsung, and now forgotten hero:

http://en.wikipedia.org/wiki/Laurie_Baker

http://www.hindu.com/folio/fo9908/99080300.htm

Very true. I visited New Delhi in December and noticed how heating/AC wasn't built in to the buildings yet it felt normal to just bundle up/unbundle up depending on the temperature. Getting rid of boilers and only boiling water when you need to is another approach that helps with energy cost - especially if they get smarter and can predict usage (on in the mornings, off when people are out of the home, etc).

Old homes (pre World War II) built in the southern United States all are centered around high ceilings, cross-ventilation. The home I grew up in wasn't air conditioned, and the summers, while nowhere near India's level, are extremely humid (90% plus most days) and are routinely above 90 degrees F.

The drawback in this is the cultural need for privacy that seems to have developed in many modern countries. People want to be able to shut their door, and this interferes with the cross ventilation. The whole "separate rooms on separate floors" also drastically hurts this concept. My house was reasonable, but my bedroom was tucked into the roofline on the top floor. It was unbearably hot, so my brother, father, and I would sleep on cots on a screened in porch.

> People want to be able to shut their door, and this interferes with the cross ventilation.

Go back a little further (1850-1900-ish) and everyone had doors that look like http://makingitlovely.com/wp-content/uploads/2013/08/MG_8405...

These work great with assisted convection. Open an attic window. Place a box fan in the window, blowing outwards. Everyone opens their windows and the hottest air in their room (at the ceiling) is drawn out through the door vents. It'll even work in single-floor apartments. Since getting a box fan (12 years ago) I've no longer needed AC to sleep at night.

Roofing also plays a part in cooling your home. The old cedar shakes roofing systems are naturally porous and enable ventilation.

Unfortunately, most people forget about this when the re-roof with asphalt shingles and rubberized underlays. The combination of the two lock in the heat.

Of course, cedar shakes tend to catch fire very easily in dry climates…

I grew up in a Florida home built around 1900, and we had no central air-conditioning until I was in my teens. The house was all windows, with 12 ft ceilings, and had even been fitted with an attic-fan, which is a kind of central fan circulation system that draws air in all the windows and pumps it out through a dormer window in the attic.

Privacy had nothing to do with our desire for air-conditioning. In fact, most of the doors in our house were removed because the house was used as a day-care for children prior to my parents ownership, who never bothered to put the doors back on. We grew up with very little concept of privacy.

We loathed the Florida summers. I can remember plenty of sleepless nights, lying awake in bed, sweating through my sheets. We wanted relief. That's all we wanted.

Also, paint roofs white, not black.

What's particularly sad is how the vernacular architectural features, which have evolved over thousands of years to deal with these issues, have been largely abandoned over the 20th century. Only to be replaced by ugly concrete buildings and AC units. These include the Malqafs[1] (windcatchers) once found all over Arabia, Egypt, and Nubia. Also the use of underground streams[2] to cool buildings. And generally not building huge south-facing glass windows when you live in a place that reaches 45°C in the summer...

Also, a personal architect-hero of mine is Hassan Fathy[3]. This man inspired generations of environment-friendly architects.

[1] http://en.wikipedia.org/wiki/Wind_tower [2] http://en.wikipedia.org/wiki/Qanat#Cooling [3] http://en.wikipedia.org/wiki/Hassan_Fathy

Thomas Jefferson designed his bedroom with ventilation in mind.[1]

[1] http://www.monticello.org/site/house-and-gardens/bedchamber

Is it realistic that you could find an underground stream wherever you want? Around 20 million people live in Mumbai. I'm just not sure it would work on that scale with tall residential buildings, as awesome as it is.

These tunnels were man-made. But yeah, obviously the scale these worked at was more towards villages and small towns.

It's sadly part of a growing faddishness with "Western" technology and developments. I find it quite sad because the local solutions are often quite elegant.

In Korea for example, they have clever traditional windows that open like normal windows, but also draw up completely and hang from the ceiling, turning your house or other structure into a pavilion. Large roofs provide lots of shade.

In the winter, you literally light a fire under the floor of the building and radiant heat warms the entire structure.

Some of these things carried over into the modern age, but many sadly did not. They're remarkably comfortable and energy efficient dwellings.

http://www.youtube.com/watch?v=kJ21SchGpsQ

> In the winter, you literally light a fire under the floor of the building and radiant heat warms the entire structure.

Yeah, and occasionally die of carbon monoxide poisoning.

http://www.ncbi.nlm.nih.gov/pubmed/22948168

> And generally not building huge south-facing glass windows when you live in a place that reaches 45°C in the summer...

People love south-facing rooms with giant glass walls in Japan. I asked several people about it and the most common (sensical) response that I got was that it makes it much easier to do laundry since people hang things out to dry.

Anecdotal observation: I just checked my monthly consumption since the beginning of this year and it averaged to 154kWh per month. I'm in Finland, I live in a flat and we have an electrically heated sauna that we use on a regular basis which isn't exactly very energy-efficient and, to think, we don't generally try to minimize the consumption of electricity at all, really.

Just wondering, what sort of consumption does that 200kWh include?

I am as baffled as you are, which is why we started keeping track of monthly readings. One of my acquaintances has a store selling electrical goods, and he too was very skeptical. We have a refrigerator, an electric cooker, water heater, TV, a PC, and other usual stuff. I used to leave the water heater on in the winter months. A faulty thermostat in the water heater is my best guess. I'll try this hypothesis out this winter, and probably buy a new one in summer. Anyway the possible culprits are few, so hunting it down should be easy.

(But the A/C unit's consumption is believable - it is rated at 1.8 units per hour, so around 5 hours usage for 30 days should push the usage up by 300 units.)

I live in Las Vegas. Deaths occur in homes here every summer due to AC system failures (usually among the elderly and children that cannot easily leave and go to a cooler place). Many more do not die because they realize it is getting too hot and do whatever they have to do to get to a cooler place. A device like this that changes your perception of whether it is hot or cold would likely do more harm than good here and in other extreme climates. I can see huge product liability lawsuits in their future.

I could also see this being a liability. They will probably need to take steps to mitigate the issue by adding more technology to the wrist band that help monitor health in general (health relating to heat exhaustion). This will raise the price of the product, but possibly enable them to do something like send the user (or 911) alerts when your body temperature rises to dangerous levels.

In addition to that if they put a disclaimer on the box they can get away with a lot more. Something similar to: http://en.wikipedia.org/wiki/Tobacco_packaging_warning_messa....

This is an obstacle, and how they could go about it in a way that may add to the quality of life, or one where they assume no responsibility for your health if you use this in extreme climates.

Also, I'd be interested to see if by "tricking" the body the wearer sweats less and then wouldn't get dehydrated as fast, possibly extending and improving quality of life in extreme climates... I'm far from a doctor, but you are right it needs to be looked into and addressed.

sweat cools you down when it evaporates. I could only see that making it more dangerous to wear

I don't mean any disrepect, but this comments seems a lot like the comments on the recent "Show HN: Dropbox" page from 2007, you are trying to think of a way this would fail, rather than potential uses.

Solving the issue of access to air conditioning or heating for the poor is a completely seperate issue than providing a solution to help lower our use of A/C or heating.

MIT Wristband Could Make AC Obsolete

It may be an issue with the Wired author, but the headline warrants qualification. People dying would be one such qualification. It really has little to do with the startup itself (if any). So the Dropbox allusion is just off base. People that have experience in extreme environments have reason to be wary of anything such as this. To use another analogy, its akin to taking pain medication to run with an injury. It would be irresponsible to say that such medication "would make doctors obsolete". In other words, by treating a syptom (pain) and not the problem (injury), you may actually be increasing risk (further, more severe injury). The concept of a personal cooling system itself is not science fiction or without merit. Its actually rooted in golden era of the space program. But there are resons the Apollo solutions did not look like this.

So tempted to go meta on how your comment seems like a lot of comments ever since the recent re-discussion of the "Show HN: Dropbox"... where were the nay-nay-sayers before 2 weeks ago?

Feedback such as the OP is beneficial to product development as a reminder to cover every aspect of potential improvement and protection from liability.

Feel free to go meta, don't hold back. Real feedback related to improvement and liability protection would stem from improving on the leads into the device to prevent electrocution or something similar.

OP's comment could be said of fans not doing enough to prevent deaths during extreme heat waves as well since the fan helps you feel cooler, but it may not be enough to overcome ambient temperature.

Fans can actually make you cooler by increasing evaporation of your sweat.

A fan doesn't help you _feel_ cooler, it actually helps cool your body by increasing air circulation and thus improving the rate of heat exchange. This device, OTOH, is explicitly intended to trick your body, potentially compromising its internal defenses against overheating.

OP's comment wasn't about being negative or knocking someone else's hard work; [s]he's simply pointing out what appears to be a very real safety concern in the system that needs to be addressed. Your suggestion that preventing electrocution on a device presumably powered by batteries is more safety-critical than this seemingly very real health risk that affects large parts of the world is, quite frankly, ridiculous.

Not every idea is a good idea. Not all criticism is offhand dismissal. In fact, critical evaluation is necessary to separate good ideas from bad ones.

HN may have gone a bit crazy on Dropbox when it came out, but the proper response is to think carefully on your critiques, not view all critique as "being negative" and dismiss it.

Also, seriously, how is "this device could injure someone when they aren't aware of dangerous body temperatures" not a point that should be addressed?

One could argue that the criticism Dropbox received from HN contributed to their success.

Engineers trade in failure modes. That's 99% of engineering; so to tell a site full of engineers that they shouldn't look at how an idea could fail ( especially catastrophic failure modes that could cost people's lives ) is going to get you mocked mercilessly and rightly so.

And notably; Dropbox has had some serious security issues; and it should not ( even today ) be used to handle information that is sensitive, confidential, safety-critical; or part of operating a nuclear facility. And that is true, despite the fact that it's tremendously useful and popular.

Valid point. I'm not a doctor, but I'm guessing the immediate symptoms of hyperthermia - i.e. profuse sweating, blushing - could be masked by such a device when it is tricking your brain that the skin surface temperature is lower in relation to the the actual. Core and skin surface temperatures have intricate relationships in regards to heat dispersion through blood circulation.

i clicked on the link expecting that they actually cool the blood flow like this (only using more compact wrist device instead of whole glove as we aren't talking extra quick cooling of sweating athletes)

http://news.stanford.edu/news/2012/august/cooling-glove-rese...

"The newest version of the device is a rigid plastic mitt, attached by a hose to what looks like a portable cooler. When Grahn sticks his hand in the airtight glove, the device creates a slight vacuum. The veins in the palm expand, drawing blood into the AVAs, where it is rapidly cooled by water circulating through the glove's plastic lining."

I was also expecting it to be about the Stanford cooling glove.

Most of the criticism above is because it's _not_ about the Stanford cooling glove or any technology that actually controls core body temperature. All this does is change one's perception of hot or cold. Even if it did a perfect job of that, which it won't, it won't keep you from dying of hypo- or hyperthermia. It won't replace air conditioning because it won't do anything about the humidity in the air, which is a major discomfort factor in the summer in most non-desert climates. It's an interesting bit of psychology but it could do without overblown claims, and I personally view energy-saving as falling in that category.

I think it would be easy for the device to detect the ambient temperature, and/or your body temperature, and warn you if you are getting too hot.

What if you've fallen asleep?

I wonder how changing the perception actually impacts the body's thermostat. I would gladly sweat and let my body do its thing than have a heatstroke while being tricked into thinking that it is relatively cool outside.

Agreed. I'm very wary about the affects of "tricking" a vital system of my body for long periods of time.

I can't find the article anywhere, but there was a similar idea done a while back where you would wear a 'dome' that was air-conditioned, keeping your head and shoulders cool. It worked wonderfully for keeping you feeling cool and as a result you didn't sweat.

Also as a result, you didn't notice when your body temperature was rising too high, so it did absolutely nothing to prevent heat stroke or any other forms of heat exhaustion. I'd be concerned about this wristband doing roughly the same thing.

I don't think this is something you should be wearing out for a jog, or while you work out in the fields, or similar.

It sounds great for my situation, though, where I'm sitting around programming in Costa Rica. I could turn off the A/C and let the house be its normal temperature of 85 degrees or so.

Like drinking a coffee every day.

There's been a bit of a precedent for that though, so we know how it works.

Heh, a coffee (I find it funny because I'm now at 5-6 mugs per day :-))...

I can't be for sure, but I bet it does not trick your body, just your mind. I can go out in the cold, ignore my mind telling me the discomfort of cold or warm, but I still will shiver or sweat appropriately. Still, I would likely only use something like this indoors.

Sometimes tricking the mind would help, I believe - imagine those times you get nervous and start sweating (tough interview white-board sessions?). I know for me it seems like it just gets worse and worse once it starts and I know the room isn't getting any hotter.

Making a system like this safe is easy with a tiny bit of effort.

With cheap sensors, the room temperature, body temperature, humidity and perspiration can be measured.

Run some analysis and warning the wearer about heat stroke suddenly becomes possible!

I originally read this as "Alternating Current" and I thought "Oh Gee, not this shit again."

http://en.wikipedia.org/wiki/War_of_Currents

Hehehe I read it like that also :)

Same here.

I read the headline as "alternating current" also. Usually, engineers in the United States abbreviate "air conditioning" as "A/C," where the slash, used contrary to the usual usage of slashes, distinguishes one familiar abbreviation from another. I'm surprised the Wired editor didn't catch the ambiguity.

At first I thought MIT had made AC Power Currents obsolete. An audible "no way!" followed shortly after.

First thought that passed through my mind as well :))

I had the same thought, then wondered, upon seeing the title image, why anyone would want to pass AC current through their wrist in the first place.

Yeah, I though it was going to be a cellphone charger.

The wristband is a controller for a new video game that blows Assassin's Creed away.

I like the idea of cooling people as opposed to whole buildings, but I don't like that this isn't actually decreasing your body's temperature, it just 'tricks' you into thinking it's colder/hotter outside. Perhaps it'll pave the way for clothes that can become cool or hot, depending on the temperature outside. I'd be very interested in those.

We're warm blooded. If you want to decrease your body's temperature, death is probably the way to go.

We don't feel warm because our core temperature is above 98.6, we feel warm SL that we are aware that we're having to work harder (typically through sweat) to stay at 98.6.

Likewise, it seems like you could make this safe if you could measure or estimate the user's core temperature. Should it deviate significantly from normal, shut the device off.

It's considerably more complicated than body temperature and sweating.

The body has ways of generating heat. If they do not turn off fast enough when the A/C fails, you get hot. It is entirely possible that this device could help elderly people in A/C failure, by forcing their bodies to adapt to variability instead of constant cool air.

Likewise, sudden heat will cause the skin to flush and draw a great deal of blood[1]. This imposes a greater workload on the heart and results in shock if the heart cannot keep up. Constant exposure to heat, as with this device, should force the heart to gradually strengthen as the hot season builds, increasing heat tolerance. Likewise, variability should strengthen the heart.

[1]If you ever have to enter a machine room with failed A/C, where the heat index is above body temperature, bundle up in heavy winter clothes over your whole body. Otherwise a runaway flushing response will draw heat into your body and kill you.

As someone who doesn't want to die, could you elaborate? What temperatures are you talking about that would cause that?

I am not an expert.

This page[1] says " If the dry bulb temperature is higher than 35°C (95°F), the hot air passing over the skin can actually make the worker hotter. When the temperature is more than 35°C and the air is dry, evaporative cooling may be improved by air movement, although this improvement will be offset by the convective heat. When the temperature exceeds 35°C and the relative humidity is 100%, air movement will make the worker hotter. Increases in air speed have no effect on the body temperature of workers wearing vapor-barrier clothing. ".

[1] https://www.osha.gov/dts/osta/otm/otm_iii/otm_iii_4.html

No it couldnt. Air Conditioning is not just about temperature but also humidity, which this doesn't address. I think room fans would still be necessary to keep the air moving as well. Plus, could tricking your body into thinking its cooler than it actually is be dangerous? Make sure people don't wear it while doing vigorous physical activity in the summer heat.

I believe the idea is not that it's a nervous system trick, but by heating or cooling a part of the body with high blood flow which occurs near the surface of the skin, you're actually going to impart a meaningful change on overall body temperature. Hospitals already do this for patients with hypo/hyperthermia. This could be monitored/regulated with a second band worn on the upper arm near the armpit which measures body temperature directly.

The question is more one of how much of an actual change can they impart (and under what circumstances?) given the size limitations of something like a wrist strap. My hunch is that this would need to be a fairly large system (including its power source) to have a meaningful impact outside of sedentary activity in an environment which is mildly under/over temperature. So good news for people who get chilly working long hours in their cold offices (which is a completely viable market), but not for runners looking to shed gear. Maybe there's something there for cyclists though, but only if they're willing to put up with a wheel generator.

Also, humidity impacts comfort largely because of its impact evaporation rates. Reducing body temperature reduces the rate of perspiration, in turn reducing the impact of humidity. You're right that it won't eliminate the effects of very high humidity, but it would reduce them.

>I believe the idea is not that it's a nervous system trick, but by heating or cooling a part of the body with high blood flow which occurs near the surface of the skin, you're actually going to impart a meaningful change on overall body temperature.

From the article i understand that it is a nervous system trick: "The research suggested that anything with a temperature change greater than 0.1 degree Celsius per second would produce the effect".

Ah... I just reread, and you're correct. Apparently I shouldn't post to HN while groggy...

From my very limited experience SF is not that humid, yet has a lot of AC.

Things like painting roofs silver or insulating buildings are great starts to reducing AC use. (Dark roofs can reach 66C to 88C in hot weather, better roofing helps a lot. (http://www.epa.gov/greenhomes/ReduceEnergy.htm#advhome))

But this? I'd freakin' love to try something like this. I'm almost always too hot, even in England.

I can imagine this being great for the winter in england, you're always moving between hot/cold environments.

My body naturally gets very warm, very quickly, with very little exercise. If they can make this work, I might actually be able to wear a suit all day! Luckily I don't need to but that's beside the point.

Assuming they can get the size and look sorted so the average consumer doesn't become a social pariah by wearing one (calculator watches come to mind), I wonder how this is powered? And more importantly, would it last for 8-12 hours on a charge?

If they're using Peltier devices it's probably going to require a largeish power supply, and some kind of heat dissipating/gathering device. One possible way to get around this for something like a suit jacket might be to move it from the wrist to the upper back, and to sew thin copper wires into the jacket. Also you could probably get away with having a few thin LiPoly cells placed in pockets around the jacket. Couple it all with an inductive charging coat hanger, and you've got a product worthy of SkyMall!

Isn't this related to fitness? If you're physically fit you don't get hot so quickly.

It often is, but I'm in pretty decent shape. I cycle regularly (my commute is 34 km one way), am not overweight and eat decently. For as long as I can remember, I've always started sweating very easily.

Is this actually true? I'm not calling you out, but I see it reported in comments all the time, but I've never read anything about it. I failed with a quick search.

Beyond that, this whole discussion just went down in another thread, but I'm like the parent post...I just sweat easily. Even when I was younger in great shape (4-6 hours of basketball daily) I would sweat quickly and profusely. I read that some percentage (~15% I believe) of people sweat more than others.

I haven't looked into any research about this, but anecdotally I find this to not be true. Having peaked at 215 lbs. and ~12% body fat at 5' 11", (I'm now closer to 195 lbs. and ~10% body fat) I'd say that I'm in the top 1% in terms of muscle mass. I am often very hot. My theory is that because of the added muscle mass (which requires much higher food intake), I'm metabolizing food at a higher rate and thus generating more heat. I don't know if this is actually the case, but it's my theory.

This may not be the case for people who are fit in a more cardiovascular sense.

I'm 6'1" and a solid 215 pounds. I do powerlifting and Brazilian jiu jitsu. I get hot quickly. I've had training partners tell me that I "run hot", that compared to others, I feel like a furnace.

Interesting article - awfull title

The device can make you feel a bit better but it can NOT replace an AC.

It was never designed to replace an AC.

If this was up for purchase i would get one especialy because it is portable and maybe it can be coupled with additional technology (measure blood preasure , acceleration, rfid access tags,...). People have been wearing wrist bands for ages (and even used them as currency) so it seems a good position for a gadget.

Interesting article - awfull title

Unfortunately it's the modern media's job to give things catchy titles so they do well on the social media rounds. A lot of excellent stuff fails to do well on HN because it hasn't got the right title (I'm an HN firehose dweller so I get to enjoy a lot of the hidden gems :-)).

Indeed, I'm pretty sure there's room for an "off HN" type site that solely focuses on the best HN submissions that didn't make it for whatever reason.

Thank you MIT for this opportunity to be found frozen to death and smiling happily

Heh, I tackled the same problem a few years back in college, but with robotics and computer vision. I prefer this approach.

You made a robot that followed you around and fanned you?! Very impressive, is the source on GitHub? ;-)

It actually detected any life forms in a room with medical grade temp sensors coupled with a kinect and then found 'hot spots'.

It wouldn't follow you (although that could be done); it was stationary and one of the big requirements was safety (don't want a robot arm slapping you in the face while coding).

Unfortunately no, the source isn't on github, although I should put it up there.

Peltier heat pumps are inefficient; typically wanting a whole bunch of watts for achieving a small temperature gradient. So I'm wondering about the practicalities of powering this thing such that it could be worn as a personal item.

That doesn't seem to be much of a problem as the point is not to actually cool you, but to apply a temperature change of a fraction of a degree to a tiny part of skin to trick you into feeling colder.

Hmmm.... and all that waste heat from the Peltier junctions go into /heating/ the room -- making it a little warmer for everyone else.

When I stick a AA battery on a Peltier, to work out which side is which on unmarked unit, it actually does "feel" very cold really quickly. Hot side is obviously also very hot, very quickly.

I'd think it's more likely that the hot side is going to be the problem. Dissipating that heat without something like liquid cooling and active fans.

This is interesting, and in my opinion definitely deserving of the prize they got for it.

But I think it's real value (in contrast to "replacing A/C") is in developing markets, where a little wristband could really improve quality of life (in the sense that one isn't sweating to death in their shanty-town hut). Not only could it improve QoL, but it would also be much cheaper to install than a central air unit, and also much more feasible: everyone has a wrist, not everyone has an insulated home with consistent electrical service that could provide the power for a central air unit. Cool stuff!

But that wristband doesn't actually reduce your body temperature, sweating does. Unless I'm missing something obvious here??

I think the article gets it wrong. Sorry.

Having your body think that it is comfortable, especially when the environment is hazardous, would be a lose. Like filtering out the sound of smoke detectors so you can sleep easier.

That said, this would be quite useful in office situations like ours where some people whine that 75 is too hot and other complain that at 70 they need mukluks. In that situation where the office is actually at a livable temperature, if we could adjust individual perceptions to be comfortable then it would be quite useful.

On a tech front, it's an interesting use of a peltier junction device. They are horribly inefficient yet really interesting. It is, effectively, a heat pump. It will make one side colder than the other. And that part is key. You must take away energy on the hot side or the entire thing will get hotter and hotter. Without heat removal on the hot side it would get hot enough to burn you very quickly. The article says they are using pulsed heat which might presumably deal with this issue.

As others mentioned already, tricking the body like this could have negative consequences. I wonder if any studies exist on this (ice bags on the wrists or some such thing).

It brought back memories of going sculling at the peak of winter. Due to the danger of falling into extremely cold water [0] I experimented with wearing a kayaker's dry suit. It worked reasonably well. A surprising find was that wearing a wool head-cap made me overheat. It was really amazing how quickly this would happen too.

I can see this MIT gizmo having some effect because our skin is sensitive to heat flow, not absolute temperature. Not sure I'd like to trick my body that way though. What are the consequences of messing with the mechanism that maintains proper thermal balance?

[0] There have been many incidents of rowers drowning in cold water within swimming distance of the shore. Swimming in cold water while wearing thin clothes and your heart pumping hard due to the physical exertion of rowing is extremely dangerous because hypothermic effects can be greatly accelerated. Even accomplished swimmers can drown fifty feet from shore.

Hopelessly naive. An air conditioning system is used to cool spaces yes. But where I live, it is just as important to lower the humidity. This device will not help with that.

Naive? This is a proof of concept, and it makes people feel cooler. Dehumidifiers use significantly less power than cooling. The peltier they're using with a 30% duty cycle would require about 30W per person.

Dehumidify a typical room: 500W Cooling a typical room: 2000W

This is like a placebo, intended to trick you into perceiving cold or less-cold when it isn't there. But when there's a real matter at hand placebos only work very temporarily – then eventually reality catches up to you. So if it's actually hot, and my body needs to react to that to regulate my temperature, this doesn't change that. But I suppose it would let you turn the temperature up a couple degrees.

I don't think it's that much like a placebo. A placebo literally has no effect. This device actually has a cooling/heating effect that your body just perceives as being greater than it actually is.

Am I the only person who is skeptical about this? I don't see any published research. It sounds like their device just temporarily distracts you from noticing the heat or cold, in the same way that poking needles into random parts of your body distracts you from pain (aka acupuncture). I would like to see a placebo-controlled study where they having people sitting in a 35C room all day.

Interesting idea. I though it was going to be more like the 'cooling glove' [1] which actually cools you down, rather than just making you think you're cooler. Hairless skin on the hands and face has blood vessels close to the surface, and cooling those parts is proposed to quickly cool your blood and core temperature.

It looks like the energy and space requirements for such cooling glove are too large to make it portable, however, and it also doesn't work much better than simply holding an ice pack! So, for portable devices, it seems like at most we can only trick ourselves into thinking we're cool.

[1]http://www.slate.com/articles/technology/future_tense/2012/0...

At first I thought this thing hooked into your blood flow to actively cool down your blood, like watercooling does for computers, it would've been a much cooler idea (no pun intended)

EDIT: fixed autocomplete phone typo

Reminds me a little of this, though this uses a constant fan rather than a pulsing schedule of cooling jolts. I've used one before, and it works surprisingly well for such a low-tech contraption.

http://www.sharperimage.com/si/view/product/CoolWare-Persona...

Unless my high school biology teachers lied to me, feeling hot or cold is not a mere perception; it's homeostasis, a complex mix of body temperature control, early warning system and pre-emptive shutdown all rolled into one. I don't see how useful tricking this system is, and I also fear it is dangerous to do it, if at all it's possible to successfully do it.

I'd say the biggest market now or at least 10 years later will be China. They don't use them just for cooling but also for heating because the southern half of China has no public heating system. But that's just my instinct. Might be completely off and people in Brazil might actually use them much more.

Body temperature comfort is subtle. Is not the same 24ºC with an AC than by the sea shore, under a tree shadow with warm, slow wind.

For some reason i don't think a heat sink tricking my physical feelings will do for my quality standards regarding temperature control. I already detest AC, as in, I can't stand in ACed places.

I don't imagine this making AC obsolete. It might marginally reduce demand for AC, especially in cooler climates where AC might only be used occasionally if installed.

If made in to a product, I expect it to be popular for outdoor use. I find it appealing enough for that use case that I'm contemplating building one.

How does fooling the body into thinking the temperature is higher / lower affect the real temperature of the body? The article fails to explain that.

This is like putting a frog in gradually boiling water. The frog cannot sense the increasing temperature, so it stays in the water until its dead.

Snopes says the frog jumps out:

http://www.snopes.com/critters/wild/frogboil.asp

Yeah, I definitely don't see this as making AC "obsolete" so much as perhaps raising the threshold of when you turn on the AC. As a resident of the Deep South, this could potentially make sitting outside during the height of the summer a more pleasant experience.

This is not news. Sharper ımage already has a product like that in the market for years.

http://www.sharperimage.com/si/view/product/CoolWare-Persona...

So it's a trick? I'd rather see a thermal device that makes contact with a larger surface of one or more of my body's high-blood-flow areas and actually cool or heat it.

I've found it efficient to cool or heat myself by letting cold or warm water run over my hands.

How do you know you weren't just tricked?

There's a similar technology already being tested on athletes:

http://corecontrolcooling.com/

Cool idea. If you attached a wristwatch to the outside face, I think that'd help it take off.

Don't make AC obsolete, make it as efficient as you can and then power it from solar. The kind of people who will wear a heat pump on their wrist to try and save electricity, are not the people who run the most AC units.

Anyone had experience with Phase Change Material (PCM) clothing? Here is one supplier: http://www.outlast.com/en/technology/

I think it is the concept "anything with a temperature change greater than 0.1 degree Celsius per second would produce the effect" is very interesting. Building a device to do that is not a big deal..

I have nothing against all the energy efficiency development however many articles display a tone that everything was going well before but now due to emerging countries we are facing this havoc. Pathetic.

Hasn't there been one of these in SharperImage and Skymall for years?

This may not replace AC, but I wonder if (in colder countries) it would help with dieting. Want to lose weight, just turn your thermostat down by a degree and use this device to help you adapt to it.

Are there any indications that turning thermostats down (or up) impacts weight?

Maintaining body temperature takes energy, so being in a cooler environment would help, but it would be minimal, I'm fairly sure. Air has a much lower specific heat than water, and I remember reading a reddit discussion about drinking ice water all day to lose weight versus room temperature water. I don't remember what the result was, but it didn't take as many calories to heat the water as you'd think.

Well a calorie is the amount of energy to raise a gram of water by one degree Celsius, so if you're drinking 2 litres of water a day and it's 0 degrees vs 20 degrees, you'll burn around 20,000 calories a day from the difference.

Note though that that's calories, and not kilocalories, which is what we generally talk about for dietary purposes. So ~20kcal a day, which would represent about a 1% change for the average person. Not a huge gain.

Also, people might just eat a spoonful of more food, if they need 20kcal more per day.

How about a solar powered thermoelectric mesh woven into a short that cools my body off? Can I have a wired article if I build one, even when it doesn't work?

If the MIT team had just printed their device on a 3D printer, their article would have knocked the Nexus 5 release off the front page.

I read this as MIT wristband would make 'Atlantic City' obsolete. Perhaps some kind of card counting helper. ;)

MIT has worked on that as well.

If your body continually feels like you are jumping into cold or hot water, wouldn't that induce stress?

I think that was a layman way of explaining the technology rather then how you actually feel.

It could kill people. If you dont thermoregulate properly then you will die of hyperthermia.

Those wires are going to cramp some people's style, though.

Can't wait for the FDA trials.

Why would their be FDA trials for this?

It could be classified as a medical device under FDA regulations:http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidanc...

so if I have such a copper heat dispenser I got from taking a laptop apart, I can feel cool ?

It's not just a heat dispenser, it's a peltier [1] a device that can produce cold from electricity.

[1] http://en.wikipedia.org/wiki/Thermoelectric_effect

Well, it can transfer heat when electric current is applied. They used these for processor coolers in the 90s, I remember my father had one and it broke one day and so his processor let out the blue smoke.

I had one as well. Same experience with a brand new AMD Athlon XP 1800+.

I invented this exact concept 2 months ago. Heat sink on a wrist band. I did nothing with it, good luck to these guys.

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