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The 1/8th Sleep

near.blog

195 pointsasats54 comments

Interesting. Living in Japan there is still a strong culture to try to avoid using air conditioning at night (in particular among the elderly), so there is a whole market for both staying warm in bed during winter and cool in bed during the hot and humid summers. My own family has primarily been using mattress protectors that conduct heat more efficiently [1], towel blankets (タオルケット) [2], and gel pads than are stored in the fridge and then put under the pillow cover just before you go to sleep. There are plenty more on the market, but I have solely by using the conducting mattress protectors been able to sleep with the air conditioning several degrees higher than I would have been able to in the past.

[1]: https://www.nitori-net.jp/ec/product/7567051s

[2]: https://www.nitori-net.jp/ec/cat/Shingu/Blanket/BlanketTowel...

> in Japan there is still a strong culture to try to avoid using air conditioning at night

Why?

Superstition

There’s a little subtlety to it. In some (all?) parts of Asia it’s intentional misinformation to reduce power usage.

No I think that there's more to it than superstition - We often blame things on superstition when we don't understand them ourselves.

I've been playing around with sleeping with a fan & air-conditioning and I always notice that my throat is all dryed out in the morning from the air flow directly over my face.

I need a couple of glasses of water to re-hydrate after sleeping with a fan or air-conditioner, so if its not too warm a night I prefer to leave them off. I seem to get a better night's sleep too, but maybe that's just because it's a cooler night.

Aim the fan at your legs; in my experience it cools effectively (I assume because blood is circulating) and dehydrates less.

You should look into this more, including the state sponsored news reports of fan death.

It’s not just superstition. Air conditioned air can be bad for you if you’re not maintaining it. It is also drying so it can bother your throat, eyes, and skin. It might make it easier to transmit COVID though that might just be in door air. I definitely prefer comfortable outdoor air to air conditioned air.

https://www.webmd.com/a-to-z-guides/ss/slideshow-what-ac-doe...

https://time.com/3942050/air-conditioner-healthy/

I was just about to buy almost this exact setup! Excellent to see it's effective. I thought I was mad looking into fish tank coolers. I was thinking though skipping the evaporative cooler and going with a compressor model. Quite a bit more expensive but I think it'll be more effective in the humid North East.

I have realized over the years that I need to be seriously cold to sleep well. My health watch always registers a great sleep and recharged "body battery" when I've been almost shivering all night. My partner likes to joke that my body needs "suffering to get fully rested".

These days, I only ever have nightmares when I'm too hot. It's a challenge to stay cool enough to not get them.

I did recently switch mattresses to this Airweave Futon: https://airweave.com/products/futon

It's an amazing product, it helps keep me cool, and is nice and firm, which I need to have a restful sleep without back pain. By far my favorite mattress I've ever used.

The Airweave has reduced my hot nights significantly, and I'm thinking if I can put a cool pad underneath it, I'll be set!

I'm going to have to try this DIY project for sure now!

A reviewer on reddit complained that the airweave wore out after a year, which is disappointing given the price. How long have you had it?

I would be disappointed as well!

I got it a year ago, still feels like new. However, I got the very thin Japanese futon model, and my partner and I are both under 145lb/65kg so that probably goes a long way. I could definitely see a heavier load compressing the coils permanently.

I did see this on their FAQ page:

"Up to what individual body weight is ideal for an airweave? We have tested our mattresses for individuals up to 220lbs. At this weight or lower, you should expect to use your mattress for 10-15 years. For any individuals above 220lbs you may see body indents and wear sooner"

I also see that the warranty is good for only 3 years for the futon model, which leads me to believe I'll be shopping for a new one in 2 years. That's... Not a long time for the fairly steep price of $2600.

When this wears out, I'll probably go back to a thin cotton futon, that's my second favorite. I only got the Airweave because my last cotton futon got moldy because it's so humid here it never gets to dry out.

> Compressor

I would think these would be too loud for a comfortable sleep environment.

You could put a small compressor outside and connect a well-insulated hose to pump the refrigerant inside, just like a split system air conditioner. Then the noise in your bedroom will be no worse than the occasional hum of a fridge in the other room.

As someone who lives in a humid climate, I wouldn't even think of using an evaporative cooler anywhere in my home, for any purpose, period. It's either compressors or nothing.

I believe the Eight sleep uses a Peltier cooler. Not terribly efficient, but the ΔT and the load are low (a human body puts out <100W while asleep). Plus, a Peltier can also heat with some supporting electronics.

Does the water need to be that cold? I would think the cooling can be accomplished just by having a large enough water tank and possibly a radiator and fan so that the thermal mass would prevent your body from heating it up for the 8 hours or so you spend on bed.

What room temperature are we talking? I used to think I could not be too cold at night, until recently I lived in a place that was seriously cold (basically no insulation). Turns out there is a limit! Room temp would easily drop below 15 degrees, often closer to 10!

Sounds like Australia in winter, further inland and south...

I definitely sleep really good with a thin sheet down to 60F/15C. Below that, yeah I'll put in a blanket.

For reference in 2022 I winter hiked the southern half of the AT, and it was below freezing every night for months. I did have a sleeping bag, but I slept great! I curse/blame my Scandinavian genes. Too pale for the equatorial sun and sleep like a furnace all night.

> My health watch always registers a great sleep and recharged "body battery" when I've been almost shivering all night.

Would you mind sharing which watch (model) offers this? I guess a Garmin of some sort?

I see the same results on both the Vivosmart 4 and the original Instinct. Both Garmin.

I think most Garmins have it. I have a Venu 3 and am very happy with it, the killer feature for me is it getting over a week of battery life on a single charge vs the apple watch with it's 20 hours.

> […] I was put off by the product due to the now-mandatory paired subscription ($200/yr with purchase, annually paired only, can cancel after) […]

It is both confusing and fascinating how some companies manage to put out a product with a subscription, the existence of which defies logic and consumer expectation, and yet they manage to find a group of people who tolerate it.

This is the new venture capital model. Everything must be (or come with) a subscription.

It's a way to take an area that has low technological innovation (little reason to buy next year's cooling mattress, which is the same as last year's mattress) and turn it into recurring income.

As a bonus, all the smart features that you bundle into the subscription are also the personal data of people with high disposable income. You can now make money twice.

Not just venture capital. Established businesses too

Investors like recurring revenue because it's simple to understand. You can just slap a multiple on it to figure out the valuation of a business

When ARR is the only metric an investor cares about…

Your bed needs to be breathable. That's the single most important thing. A cool bed without proper ventilation will attract condensation and mold, and make you feel damp.

A good spring mattress sitting on top of slats will never get uncomfortably hot or cold in any particular spot, because air moves freely in and out, powered by your own body movements.

The mattress should also be as firm as you can tolerate. A firm mattress leaves breathable space between some parts of your body and the surface of the bed, instead of allowing your body to sink into the foam and become insulated on all sides. Again, airflow is key. Regardless of what heating or cooling solution you have, airflow will multiply its effect.

I'll add to this I find a wool blanket/duvet to be so much better than polyester/plastic. When I use plastic duvets in hotels etc it feels like I'm wrapped in a plastic bag.

Completely agreed. Natural fibers like wool and cotton help moderate humidity by quickly absorbing moisture and slowly letting it evaporate.

Synthetic fibers can be designed to channel moisture away from your skin instead of trapping it, but they can't absorb any. Besides, I doubt that hotels use sportswear-grade stuff in their duvets.

Trouble is the spring mattress manufacturers kept reducing quality to achieve a price point and then people needed the extra comfort they took away, for cheap, so hot, foam toppers became the norm.

If you want an all-natural, chemical-free, traditional hand-made pocket-sprung mattress you’re looking at £3-6k here in the UK. But I agree they are the pinnacle of mattresses, ticking every box

I feel that the vast majority of people should not need an elaborate setup to sleep well. If you need to spends hundreds or thousands of currency units on a setup beyond a basic bed, there is something wrong that could probably be fixed in a simpler way.

Right. If people are overheating at night during relatively normal temperatures, it’s probably a medical/diet issue or something in the bed is making you over heat, such as stupid foam.

I think there's a simpler explanation for a lot of people: they like sleeping under a big fluffy comforter or a heavy quilt or so have you for weight/texture reasons, but don't want to cool down the entire house just to make that comfortable.

i've bought a moderately expensive, very comfy foam bed which is however much hotter than my previous absolutely cheap 20yr old spring mattress...

I'm apalled by the fact that in 20 years we have regressed rather than improved on the temperature aspect of mattresses

Consider Northern Europe. We live in Copenhagen and approximately zero percent of apartments have air conditioning. Personally, I sleep like crap for 3-4 weeks out of the summer and I'm totally going to try this next Spring.

For myself I can sleep at any reasonable temperature. But between 60-65 F, I sleep extremely well. I do it with a relatively simple set up called an air conditioner, but I have fantasized about having a pillow that is always cool to the touch.

Great hack!

I do a cold shower before bed. Often helps.

You can start the shower warm and then slowly reduce the temperature.

Wow. I do cold showers too, but never before bed. It'd wake me up!

The method works, and I am going to elaborate on it a little. As the poster said, start warm, work your way down to cool, then cold. Very cold.

But what really seems to kick one off to dreamland is not drying your hair, instead putting a towel down on your pillow. As your hair dries, you'll get some more evaporative cooling strictly for your head, and that helps even more

Have you tried a hot shower instead just before the bed. The trick is that it cools down the core when you leave bathroom (by bringing blood to the surface).

Extremities should be warm, the core(CBT)—cold, to fall asleep easier.

I have tried that, and no luck. I think, for me at least, it's the head cooling that matters most.

Yes, I don't dry my hair. I live in a hot climate.

I also do this.

I lived most of my life in the Mediterranean country and lived in a apartment on the top floor with just a concrete roof where the room temperature was 34°C even at night.

The solution I found was to take frequent cold showers. Stay under the shower for some time, like 5-10 mins, until you get cold, and then without drying yourself, lie in bed naked. I also felt so cool that I even put a blanket over me. It takes a while until you get warm again, so it's enough time to fall asleep.

For more extreme hot situations you can put a wet cloth/t-shirt on your body, but I think that might be unhealthy.

Good! I'm glad for any alternatives to 8sleep. I have two of their beds, and love them, but bought them before they starting requiring a yearly subscription, which I HATE. Unfortunately, they are the best product available as far as I can tell. Though definitely expensive.

They require a subscription? Why does a mattress require subscription?

A cooler mattress is better to sleep on? That sounds like the opposite of my experience, unless the weather is uncomfortably warm and there’s no air con.

In my experience, I might like a cool bed if I was hot in the evening (say, I was physically active). Otherwise, I prefer a cool room with a nice blanket.

A lot of research seems to suggest that cold (something like 62F-68F) is indeed better for sleep. It makes sense if you think about it "evolutionarily" or whatever. Basically, your body feels warmth and it assumes the sun is what's heating you up, so suppresses sleep hormones and promotes wakefulness.

Anecdotally seems true for me, but I also have poor circulation to my extremities so I just suffer one way or the other.

> It makes sense if you think about it "evolutionarily" or whatever. Basically, your body feels warmth and it assumes the sun is what's heating you up, so suppresses sleep hormones and promotes wakefulness.

We evolved in places that were hotter [0] on average than where most HN commenters reside.

[0] ... unless paleoclimate in Africa was much colder than I guess it was.

and it's still colder at night there

“ unless the weather is uncomfortably warm and there’s no air con.”

I think that’s what this is for? I love a cool bed on a warm evening

Do people use this only in the hot months? It's beginning to get cooler where I live and from now until around April we do the opposite and use a heated mattress pad. For me there's nothing better than getting into a warm bed in a cold room. I immediately turn off the heat after getting in though, otherwise I overheat and sweat.

When they were less expensive, I got a Casper mattress, and it's true that I really appreciate its cooling compared to common mattresses. https://casper.com/cooling-collection

I'll build that. Because, I'm desperated 2 Months per year. I live in Paris

Classic hacker mentality!

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