Hacker News Reader

Comment by cgb223 | Hacker News Reader

I'm sitting in Noe Valley on the top floor of an A/C-less apartment

Please kill me, or send ice

Cool showers can help. Even room-temperature water is great at transferring heat away from your body as long as the room is at less than human body temperature. Also, if you have a fan, this is a great time to point it directly at you. If you don't have a fan, Walgreens should be open for the next sixteen minutes.

(I'm in similar straits at the moment, but feeling fine.)

I've been told hot showers are better. Opens your pores allowing your body to cool itself. I don't know if it is "true", but from personal experience, it works.

I'll just hedge my bets and take an awkward lukewarm shower

Take this advice from a person that has lived with no A/C in hot and humid north east summers: cold showers at night go a long way to helping you get to sleep on hot nights.

A hot shower would dilate your blood vessels and thereby bring your blood vessels's walls closer to your skin to enhance dissipation of heat. But if you're coated in water that's warmer than you, you're going to heat up.

That's why the key is a fast hot shower. Get the vasodilation effect going, then park in front of a fan for some sweet evaporative cooling.

I'm sorry, but please think very carefully about this. Exactly how would "closed pores" change thermal regulation? You don't need a biology degree to work out that this is at best a minor effect compared to evaporation.

You're bathing yourself in hot water which will raise your body temperature. Afterwards it'll evaporate and remove some of that energy and by compariosn, yeah it'll be cooler.

But you can get the exact same effect by taking a cold shower.

> Exactly how would "closed pores" change thermal regulation?

Less sweat, where the cooling mechanism is evaporation.

It doesn't matter at all if the water evaporating from your skin is sweat or from the shower, the phase change is what transfers thermal energy from your body. So, cold water will remove slightly more heat warming to the point of evaporation (about 4 joules per gram per degree Celsius difference) but the latent heat of evaporation of water is about 2000 joules per gram, which is much more than the difference between hot and cold water. So it doesn't matter that much whether the water is cold or hot, just that it evaporates off your skin and takes the heat with it.

Umm, no. If you are hot, the last thing you want to do is add more heat.

Yeah! Although, I don't know how well that would work when the ambient temp exceeds normal body temps.

Anecdotally a really, really fast hot shower is great for cooling. Like less than a minute, probably more like 30 seconds. Then park your butt in front of a fan to get some evaporative cooling and relax for as long as it takes.

    Opens your pores

I don't know about that. I've always figured the key here is vasodilation, which helps the body shed heat. Opposite of vasoconstriction obviously. A cold shower causes vasoconstriction, while simultaneously not providing enough surface area contact between you and the water to effectively change your body temp.

https://en.wikipedia.org/wiki/Vasodilation

It's pretty well accepted, isn't it?

http://theconversation.com/health-check-do-cold-showers-cool...

Of course, if you really want to change your body temp, there's no substitute for total immersion in a bathtub or swimming pool. There's a reason why this is how it's done in a medical setting.

parents in some of my local fb parenting groups are frantically sharing locations of any stores in the city still selling fans. looks like most of the places you'd hit up (costco, target, bbb, hardware stores) are all sold out. so is prime now. walgreens may not have any fans even as a last resort - some of the locations seem to be sold out too. it's worth calling ahead and asking.

prime now wasn't sold out of things like ice cream though, and maybe they still have things like cooling towels in stock? i was swapping my cooling towel with my baby earlier today.

Cooling towels are great. My 10 yo stepdaughter had one for three days at Universal Orlando in August, 95 degrees, 90 percent humidity, and it saved the day(s).

Any towel can be a "cooling towel". Evaporative cooling works without any special technology.

https://www.consumerreports.org/cro/news/2013/08/consumer-re...

One of the most effective ways to cool is to wear something thin top and bottom, then wet it (just jump in the shower with your clothes on if necessary) evaporative cooling works much better, the more fluid there is. In Saudi, when people get heat stroke, they cover them with wet sheets, then use the fans, much more effective than just fans, or ice packs. Or when you go to sleep, strip off and sleep with a wet sheet over you, and just wet it again if it dries out during the night.

Keep the humidity in mind if you do this. Out in Saudi it is the desert so evaporative cooling works outstanding. Where I am the humidity often gets up to 100% overnight so you would just be sleeping with a soggy warm sheet all night.

I've got cold beers on 29th if you want.

I appreciate it

Just jumped on BART to crash at a friend's place who has A/C

I'm new to the area though and always looking to make new friends!

Maybe another time?

Get a spray bottle of anything at the dollar store, dump out and fill with water. Also, box fans are like $20.

If it were me I'd seriously consider staying in a hotel for a day or two. Hope you are okay.

Reply on news.ycombinator.com