To my knowledge the only way to stay cool in high heat and high humidity is with ice. An ice vest, ice hat, etc
There are devices like scarves or hats that hold moisture and help wick away heat as the moisture evaporates, but they only work in low humidity environments. Same with a personal misting device, doesn’t work if humidity is too high.
There are some devices like neck fans, kind of like a brace that goes around your neck, but doesn’t air circulation to deal with heat stop working around 95F? If you’re in portland and its 115F I don’t know if that would help any.
So aside from rubbing ice against your body, is there any way to stay cool in high temperature, high humidity style heat?
I’m guessing conduction by putting a cold object against your body is the only method in high heat and high humidity.
Are there devices that have an exothermic reaction that can also be recharged? There are devices to keep warm in winter that have rechargeable heat, they can be recharged by submerging them in boiling water or with electricity. But I don’t know if there are any endothermic items that can be recharged somehow.
You can buy phase-change-material (PCM) ice vests. I think they are mostly used when enveloping protective equipment is required. I don’t know anything specific, but I’ve never heard of them being used in mines – AFAIK mines just try to refrigerate the general air temperature low enough to allow work.
A ‘space suit’ is exactly what is described: an insulated air-conditioning work suit designed to keep astronauts from overheating.
Alcohol, on those little spray bottles for hand sanitizing worked very well for heat relief. I have basically a lifetime supply via the fire department I volunteer for. I have brought them on bike rides and found out that they can be used to cool off even in the most hot and humid days. By spraying them on my clothes and skin there is instant relief and it feels really good, and it doesn’t take much. Also it doesn’t last all that long (though a bit longer then I would have expected) but sometimes just a moment of coolness is all you need.
A few years ago in 2018 I was in Germany for the hottest week of the year during the hottest summer they’d had since, possibly ever (at the time). We were on vacation (in Europe for a wedding; I would not have chosen this time of year to go if I’d had a choice) so we were still insistent on going out and doing stuff, and one of the things we did was visit Bacharach and walk up to Stahleck Castle, way up above the town. I was hot as shit when we made it to the castle and inside they had a knock-off Slurpee/ICEE machine. A small cup of that stuff cooled me down in just a couple of minutes.
So my suggestion is “get the biggest insulated tumbler you can find and fill it with some type of icy slushy drink.” Plain frozen berries or cut fruit would work too, if you happen to hate Slurpees/ICEEs.
(FYI Wirecutter tested a bunch of insulated tumblers, filling them with Slurpee and leaving them in the front seat of a car on a hot day; they all lasted at least a couple of hours, with the best still at least partially frozen after 5 hours)
Some people do make cooling vests and the like that use peltier coolers. I don’t know how well they work.
For those who don’t know what a peltier device is, it’s basically an array of little semiconductors. When you run current through them, they work like a bunch of itty bitty heat pumps, so one side of the device gets hot and the other gets cold. From a thermodynamics point of view they are horribly inefficient, and you need something to draw the heat away from the hot side or they’ll quickly overheat. On the plus side, they are small, lightweight, and have no moving parts. Also, if you reverse the current then the hot side gets cold and the cold side gets hot. Because of that you can actually use them for fairly precise temperature control. They also work in reverse, in the sense that if you apply a heat differential between the hot and cold sides, they’ll generate electricity. Again, they are horribly inefficient compared to other methods of generating electricity, but they do work.
They were originally developed for space satellites, and were ungodly expensive. When they became dirt cheap, people started using them for CPU coolers in home computers. You can also find them these days in other things like portable picnic coolers. If you have a camping cooler that plugs into a cigarette lighter socket, chances are it’s based around a peltier device.
There is a big trade-off between how much cooling you can effectively get out of a bunch of these devices vs. how big your batteries need to be and how long those batteries will last, so while I know some folks have made wearable devices like vests, I don’t know how truly effective they are.
Yes, drinking something cold is the most effective thing I’ve found. As a bonus, it wards off dehydration, which is always a risk in high temperatures.
Clothing that covers more of your body is a counter-intuitive but useful strategy. Once outside temperatures approach your body temperature, having bare skin exposed to the breeze is no longer useful for cooling, and blocking the radiant heat from the sun becomes more important.
I would worry a little bit about surrounding myself with a cloud of flammable vapor, although I guess it’s not such a risk if it’s in very small quantities or there’s much airflow.
Thanks for that, I have not considered it and usually don’t come up across open flames on my bike trip. I did an experiment, and this is 70% isopropyl . Using an open flame of a camp stove I sprayed it with the alcohol spray, the blue flame turned orange and did expand a bit around the fuel source but did not follow the spray, it was very localized around the flame. I gave it 5 good shots and no spreading, leading or following beyond again some local expansion. Next I took a piece of paper and sprayed it as if I were to spray myself and lit it. It burnt like paper, nothing special was noted. I then wet it to saturation and lit it. I got a pretty good spreading/engulfing blue flame over the paper which I was able to extinguish with my hand without burning my hand. Overall while I would not recommend lighting a joint while using this method, it does seem like it’s not the worst substance to use.
A college roommate got one from a surplus place and we were goofing around with it. It had a small extruded aluminum heat on the hot side and the cool side got nice and cold. I picked it up and burned the ever living crap out of my thumb. There was a pattern of burns that matched the heatsink fins, kind of funny now but not at the time. Well, my roommate found it funny.
It melted apart shortly after. It hadn’'t come with a spec sheet or anything and I suspect we were driving it with too high voltage.
Having experienced high heat and high humidity conditions in Asia, mainly in Japan, I can say with assurance that you do not have many options, apart from acclimatizing.
Rubbing ice against your body, or drinking something very cold, makes your body think it is winter, so it tries to conserve heat. Obviously, that is the wrong way to go. If the humidity is less than about 90%, you can cool off with a wet shirt, but obviously you can only do that in a very informal setting. And yes, wearing a suit and tie in Japan in the summer was no fun.
Frankly, the only way to cope with that weather was to slow down, take things easy, hydrate adequately (lukewarm is best) and wear something that does not feel oppressive. They only appeared near the end of my time in Japan, but microfiber fabrics were a godsend, thanks to the unsurpassed wicking. Before that, the best was clothng made of open weave cotton, but cotton takes a while to dry. I also found polypropylene or Capilene undershirts (made for hiking) very good in hot and sweaty conditions.
I have encountered hot, at up to about 41C/ 105F, but it was a relatively dry heat and not unbearable. If you add high humidity to that temperature, I think I would be in and out of the shower, and just resting while out.
In my last visit to friends in Austin TX before COVID I used one of these -
It was probably around 100F and 60% humidity - so not as bad as what you’re experiencing, but I’m acclimated to Colorado at altitude, so highs around 95 and humidity around 15-20%. These things are nice, and being around your neck, actually do a good job of keeping your head/neck area (which on me is the most unpleasant areas to overheat) cool. For a bit. And I do mean for a bit. In the conditions above, they felt great for about 15 minutes, and refreshing for another 15. Then they were spent. They do claim that you’ll benefit for 40 minutes to two hours, but that probably only applies in a perfect world where you’re using it for weather in the low 80s to cool off.
A friend currently in the Seattle area said they used something more like this -
Which comes with 2 strips of reusable, flexible ice cubes in a cloth neckpiece. They bought another 6 strips of ice, and when they had to go out, they brought all of them in a small lunch sized insulated pack with a large reusable ice pack. They then cycles through the ice strips roughly ever 20-30 minutes, putting the ‘used’ ones back in the cooler. Got about 3 hours of the originals, and the ones back in the cooler got cool, but didn’t refreeze of course. Still was useful for a quick pick me up apparently.
It all fit in a smallish lunch box style cooler, and for the amount of time they were outside, was plenty, but probably not if there was any real degree of exertion. Fundamentally, as others have said, if you’re going to spend a lot of time outside in those conditions, you acclimate and/or minimize activity. And of course, hydrate or die.
Not a mine, but the Cave of the Crystals runs about 136F with humidity near 100%. Sweating doesn’t work there, and in fact you’ll actually get humidity condensing out onto your skin and warming you to fatal temps in short order. Personal portable cooling systems there are a survival requirement.
It’s a function of humidity. Relative humidity over 95% and heat over 88F is when evaporative cooling starts to becoming ineffective (see “wet bulb temp”).
I have a neck fan that I use sometimes and I really like it. Blow it on the sides/back of my neck, where there’s already perspiration, and it helps the perspiration do its job.
Also, not sure about your use case, but putting the ice compress in your groin/armpit/neck is more efficient for keeping cool. Those areas are dense in blood vessels close to the surface of the skin, so they can transfer heat better. Not sure if you want to be cruising around Portland sporting a giant diaper-bulge and side-boobs, but personally I’d find dignity a secondary concern in heat like that.
I was under the impression that fans stop working to cool you off when the ambient temperature is 95F or higher. The air the fan pushes is no longer cool enough to transfer heat away via convection.
I once had a fever of 104.2 so I put ice packs on my groin, neck and armpits. After an hour or so (I forget the exact time, this was decades ago) it was down to 102.6.
If the air is calm, a fan can help flush out the air around your body which is extra humid from your sweat with drier air that can help your sweat evaporate more efficiently and cool you off. But one key to help evaporation is to use a fan on a low setting. On a high setting the fast air can push the sweat off your skin and you don’t get the evaporative cooling effect. This is one reason that ceiling fans can help you feel cooler. The stale air around your body gets warm and humid. The gentle air circulation from the ceiling fan helps pull that stale air away from you.
