11 ms·

One thing I've noticed when coping with severe heat, and often get laughed at, is to wear a wet t-shirt. It's incredible how instantaneous the relief is. I just

One thing I've noticed when coping with severe heat, and often get laughed at, is to wear a wet t-shirt. It's incredible how instantaneous the relief is. I just take an ordinary cotton shirt, fold it neatly into a small packet and run it under the tap. Press it a few times so the water runs through the folded package and then unfold. Don't wring it as it will stretch the cloth beyond repair, and put it on. Initially it will feel weird and uncomfortable, but once it's on I feel my head getting more relaxed by the instant. You can even take a comfortable jog outside in 35C in the blasting sun for up to 10 minutes. The shirt will be near dry by than and it will get uncomfortable very quickly, but think of the possibilities! On extreme days I just wetten the shirt for 4-5 times a day and put a fan on me. No sweat when facing >35 degrees inside. I tried it with pants as well but if you do so, don't wetten it above the pockets as the multi-layer will make it damp without much of the adiabatic cooling perks.

__s 5y ago
Similarly, run your head under cold water
- sneak 5y ago
  I find that drinking near-freezing-temperature water also helps, although it's somewhat limited by your stomach's ability to transfer heat. I think the cold constricts blood vessels in the stomach and limits the total amount of heat-transfer-per-second pretty quickly, resulting in a "water baby" that takes 20-30 minutes to come up to temperature and leave the stomach. It's great the first couple minutes, though.
- whymauri 5y ago
  Bingo... when I was a kid, we lived south of Miami and were part of a cult (different story for a different time, lol). We spent a lot of the summer time on intersections handing out miscellaneous religious texts to commuters in their cars. In any case, the wet t-shirt concept was too uncomfortable and chaffed. Instead, we ended up taking our baseball caps, dipping them in freezing cold water coolers, and putting them on our head. You'd get like, 20 minutes of relief before returning to dunk the hat again. Having the soaking hat drip on your face and neck provides a similar experience to running your head under cold water without needing an accessible spigot.
gruez 5y ago
The effectiveness of this technique depends on the humidity being low. If you tried this when it's 80+% humidity it probably wouldn't do much.
- asdfasgasdgasdg 5y ago
  Was it in fact that high of humidity in BC during this event? I think it wasn't, right? When I looked at Portland's weather on the day it was really hot there, the humidity was around 20%.
  - refurb 5y ago
    In the interior of BC it’s typically quite dry during the summer. It’s basically high desert at least in the south.
  - xyhopguy 5y ago
    At 49C you need a dewpoint of almost 70 (!!) to get 20% relative humidity. thats nasty -- during the heatwave in portland the dewpoint was between 63-68 most days. Usually its ~55. For context, the dewpoint on the east coast during the storm season usually is between 70-75.
- Cthulhu_ 5y ago
  Or when it's over 52 degrees outside, when "wet bulb" temperature (= a thermometer in a wet cloth) goes over 35, which is what they've been having in Pakistan. At that temperature, the evaporative cooling effect of water (like sweat) is no longer enough to manage temperature, and even fully healthy and hydrated people can die from heat exposure. I mean I watched people in Canada in the news this morning and thought, why are they still outside in the sun even?
  - klodolph 5y ago
    Just to elaborate on the "thermometer in a wet cloth" explanation... If you have water at the wet bulb temperature exposed to ambient air, then evaporation and condensation are in equilibrium. Above the wet bulb temperature, there is more evaporation, transferring heat from the water to ambient air. Below it, there is more condensation, transferring heat from ambient air to the water. Except at 100% humidity, this is higher than the dew point, which is the temperature where water spontaneously condenses out of the air.
shadilay 5y ago
You can also sleep under a wet towel.
GekkePrutser 5y ago
Yeah your T-shirt is basically doing the sweating for you then. It's the same mechanism.
cheschire 5y ago
You can do this with a wet sock to cool down water bottles in the desert. Maybe that helps someone at burning man one day.
wil421 5y ago
What is the humidity when you try this? I am guessing dry and arid.
- draw_down 5y ago
  That tends to be case in the northwestern US this time of year, so I’m guessing that’s true for BC as well. So, it seems like good advice to me.
HumblyTossed 5y ago
If you're in Florida, you don't even have to use the tap. Just put on a dry t-shirt and stand outside for a short while.
- tehbeard 5y ago
  Also works like that in Britain half the time :/
  - xyzzyz 5y ago
    Different mechanism in Britain though.
- ezekg 5y ago
  Works this way in TX too. Better yet, just go grab the mail and you'll be set. :D
MeinBlutIstBlau 5y ago
That actually sounds like a better idea than me dousing myself during a run. But then again, I wouldn't jog in this heat. My cap for outside running is about 95*F here in the midwest. If anyone wanted to know my cold temp it's about -25*F including wind chill.
mytailorisrich 5y ago
At 49.6C air must be as dry as possible and people likely need a source of colder water as well in order to have a chance of survival because that's obviously extremely hot (body must somehow be able to be 12-13 cooler than air!) See [1] [1] https://www.carbonbrief.org/billions-face-deadly-threshold-heat-extremes-2100-study https://www.carbonbrief.org/billions-face-deadly-threshold-h...
tyingq 5y ago
You can find cheap (~$5) neck wraps made of PVA fabric that do really well at this evaporative cooling effect.
lettergram 5y ago
Another tip I’ve seen, if you have heat over 100 you’re not supposed to use a fan. The moving air removes the cooler air slightly above the skin and replaces it with warmer air. Under 100 it’s good to use a fan. Running water (such as a stream) is going to likely be better as you rarely have 100 degree water, but I’m assuming the same applies.
- hetspookjee 5y ago
  My reasoning is that the cooling actually comes from adiabatic cooling, so using a fan to speed up the evaporation will improve the cooling effect. Mileage may vary though considering the humidity and temperatures.
  - devenson 5y ago
    I think you mean evaporative, not adiabatic.
jokoon 5y ago
I've already done that, the t shirt will have a bad smell, and I'm not sure it's very good for the skin. 10min is not very long. Also, gravity will make the water drip down, and the t shirt will not retain a lot of water. Maybe use a thicker cotton. It feels good at the beginning because the water is cold, but your body will heat the water and it won't be that good. There are special small tower make of platic fiber that will retain more water. The best way is to drink a lot of water, to use an small pump atomizer that you can refill. Wetting your hair as it can retain water is also a good solution.
- hetspookjee 5y ago
  The smell will come later. I'd recommend washing the shirt after a day to remove the bad smell. The 10 min is in the full sun while exercising. Sitting behind a desk in a closed environment I'm able to wear it for ±1-2 hours with effective cooling. If the shirt is dripping water, it's too wet and you should press out the water more. Also a thicker cotton feels less comfortable in my opinion, I prefer to wear a thin one and wetten it more frequently!
Causality1 5y ago
If I jogged for ten minutes in 35c my shirt would be wetter than it was when I pulled it out of the sink. No sweat when facing >35 degrees inside. Why in the world would you have to deal with >35c inside? Do you do construction? Frequent power failures?
- pjerem 5y ago
  35°C inside can totally happen in a house or an apartment without AC and window shutters.
- skrebbel 5y ago
  I love that you simply cannot imagine that houses without air conditioning could exist. In a thread about the weather in Canada, even.
  - Causality1 5y ago
    Having no AC because it rarely gets hot is like having no roof on your house because it never rains. It's a silly risk to take, especially when heat pump systems cool and heat the house equally well and much more efficiently than furnaces or resistive heaters.
    - skrebbel 5y ago
      I live in a developed country where, I estimate, less than 1% of houses have AC.
- auxym 5y ago
  Not sure about BC, buy here in Quebec, not everyone has AC. I mean, it's not that uncommon, but off the top of my head I'd head estimate that roughly a third of people have AC? Of course, when a heat wave comes, everyone wants to buy one of those windows or floor units, but then they sell out at every store in a few days. I don't have AC in our house, but we do ga e a basement that stays cool even in extreme heat. Not that fun living in a basement, but realistically the AC would only get used a few days a year in average.
monkeynotes 5y ago
The answer to climate change is to wet a t-shirt and sit next to a fan in your damp armchair while watching the world burn. Talk about frog in a pot.
- recursive 5y ago
  At least it's something that can be done.
- EForEndeavour 5y ago
  Why equate a clever tactic for instant relief for an individual stuck in a potentially fatal heat wave with "the answer to climate change"? Does the inexorable rise in atmospheric CO2 somehow make it unacceptable for a person to seek relief from heat?
  - monkeynotes 5y ago
    It was really a flippant comment on the state of the world today. I think it's still relevant. We are dealing with the affects very well, but not the cause. This is typical of how humans function and worth pointing out if only for gallows/morbid humour.
- missedthecue 5y ago
  According to Lancet, extreme cold kills 20x more people than extreme heat every year. As summers get hotter and winters become milder, fewer humans will die on account of extreme temperatures.
  - EForEndeavour 5y ago
    Got a link to the source for that ratio? Also, your conclusion definitely doesn't follow from that ratio alone. A simple example: Before: cold kills 20 people, heat kills 1 person. Cold kills 20x more, for a total of 21 deaths. After: cold kills 15 people, heat kills 15 people. Cold kills the same number of people as heat, for a total of 30 deaths.
tomcooks 5y ago
Why not wet a kiffeya or a scarf and wrap it around your neck? Cools you faster
- hetspookjee 5y ago
  You could do both =). Make all your clothes wet and let adiabatic cooling do it's work for you
bb101 5y ago
You can also buy ice packs that you wear draped around your neck. It cools the blood flowing to your cartoid artery, along with the general area. Works really well.
truenamenofame 5y ago
I have to deal with this problem living in a room with no AC/central air and I have some tips that may be useful for others in the same situation. 1. Put a frozen water bottle under your shirt. Keep backups in the freezer to cycle from. It seriously feels amazing and sucks the heat out of your body. 2. Use two or more fans, one good one to blow air at yourself and another one that is redirecting hot air away from you (so it's facing somewhere away from you). It's just like how airflow in a computer works I guess lol 3. Have ice always available, drink a ton of ice water and stay hydrated. The difference between doing these things and not doing these things for me is having a somewhat productive day vs spending the whole day doing nothing.
jonpurdy 5y ago
This works extremely well on a motorcycle at any speed above 20 km/h, even under protective gear (the only way I've tested). So well that I actually feel a bit cold at first when it's hot but not extreme (below 30°C).
pvaldes 5y ago
Exact. And a similar trick can be used with a bed sheet hanging extended in rope for cooling your bedroom in very hot nights.
mark_l_watson 5y ago
I live in the mountains of Central Arizona, and I do something similar. On really hot summer days, I will take a 45 second cold shower ever few hours. Probably not so healthy to shock the body, but it helps with the heat. About ten years ago we installed solar panels so now air conditioning is basically free during the day, but I still like the ice cold showers.

__s 5y ago

Similarly, run your head under cold water

sneak 5y ago
I find that drinking near-freezing-temperature water also helps, although it's somewhat limited by your stomach's ability to transfer heat. I think the cold constricts blood vessels in the stomach and limits the total amount of heat-transfer-per-second pretty quickly, resulting in a "water baby" that takes 20-30 minutes to come up to temperature and leave the stomach. It's great the first couple minutes, though.
whymauri 5y ago
Bingo... when I was a kid, we lived south of Miami and were part of a cult (different story for a different time, lol). We spent a lot of the summer time on intersections handing out miscellaneous religious texts to commuters in their cars. In any case, the wet t-shirt concept was too uncomfortable and chaffed. Instead, we ended up taking our baseball caps, dipping them in freezing cold water coolers, and putting them on our head. You'd get like, 20 minutes of relief before returning to dunk the hat again. Having the soaking hat drip on your face and neck provides a similar experience to running your head under cold water without needing an accessible spigot.

gruez 5y ago

The effectiveness of this technique depends on the humidity being low. If you tried this when it's 80+% humidity it probably wouldn't do much.

asdfasgasdgasdg 5y ago
Was it in fact that high of humidity in BC during this event? I think it wasn't, right? When I looked at Portland's weather on the day it was really hot there, the humidity was around 20%.
- refurb 5y ago
  In the interior of BC it’s typically quite dry during the summer. It’s basically high desert at least in the south.
- xyhopguy 5y ago
  At 49C you need a dewpoint of almost 70 (!!) to get 20% relative humidity. thats nasty -- during the heatwave in portland the dewpoint was between 63-68 most days. Usually its ~55. For context, the dewpoint on the east coast during the storm season usually is between 70-75.
Cthulhu_ 5y ago
Or when it's over 52 degrees outside, when "wet bulb" temperature (= a thermometer in a wet cloth) goes over 35, which is what they've been having in Pakistan. At that temperature, the evaporative cooling effect of water (like sweat) is no longer enough to manage temperature, and even fully healthy and hydrated people can die from heat exposure. I mean I watched people in Canada in the news this morning and thought, why are they still outside in the sun even?
- klodolph 5y ago
  Just to elaborate on the "thermometer in a wet cloth" explanation... If you have water at the wet bulb temperature exposed to ambient air, then evaporation and condensation are in equilibrium. Above the wet bulb temperature, there is more evaporation, transferring heat from the water to ambient air. Below it, there is more condensation, transferring heat from ambient air to the water. Except at 100% humidity, this is higher than the dew point, which is the temperature where water spontaneously condenses out of the air.

shadilay 5y ago

You can also sleep under a wet towel.

GekkePrutser 5y ago

Yeah your T-shirt is basically doing the sweating for you then. It's the same mechanism.

cheschire 5y ago

You can do this with a wet sock to cool down water bottles in the desert. Maybe that helps someone at burning man one day.

wil421 5y ago

What is the humidity when you try this? I am guessing dry and arid.

draw_down 5y ago
That tends to be case in the northwestern US this time of year, so I’m guessing that’s true for BC as well. So, it seems like good advice to me.

HumblyTossed 5y ago

If you're in Florida, you don't even have to use the tap. Just put on a dry t-shirt and stand outside for a short while.

tehbeard 5y ago
Also works like that in Britain half the time :/
- xyzzyz 5y ago
  Different mechanism in Britain though.
ezekg 5y ago
Works this way in TX too. Better yet, just go grab the mail and you'll be set. :D

MeinBlutIstBlau 5y ago

That actually sounds like a better idea than me dousing myself during a run. But then again, I wouldn't jog in this heat. My cap for outside running is about 95*F here in the midwest. If anyone wanted to know my cold temp it's about -25*F including wind chill.

mytailorisrich 5y ago

At 49.6C air must be as dry as possible and people likely need a source of colder water as well in order to have a chance of survival because that's obviously extremely hot (body must somehow be able to be 12-13 cooler than air!) See [1] [1] https://www.carbonbrief.org/billions-face-deadly-threshold-heat-extremes-2100-study https://www.carbonbrief.org/billions-face-deadly-threshold-h...

tyingq 5y ago

You can find cheap (~$5) neck wraps made of PVA fabric that do really well at this evaporative cooling effect.

lettergram 5y ago

Another tip I’ve seen, if you have heat over 100 you’re not supposed to use a fan. The moving air removes the cooler air slightly above the skin and replaces it with warmer air. Under 100 it’s good to use a fan. Running water (such as a stream) is going to likely be better as you rarely have 100 degree water, but I’m assuming the same applies.

hetspookjee 5y ago
My reasoning is that the cooling actually comes from adiabatic cooling, so using a fan to speed up the evaporation will improve the cooling effect. Mileage may vary though considering the humidity and temperatures.
- devenson 5y ago
  I think you mean evaporative, not adiabatic.

jokoon 5y ago

I've already done that, the t shirt will have a bad smell, and I'm not sure it's very good for the skin. 10min is not very long. Also, gravity will make the water drip down, and the t shirt will not retain a lot of water. Maybe use a thicker cotton. It feels good at the beginning because the water is cold, but your body will heat the water and it won't be that good. There are special small tower make of platic fiber that will retain more water. The best way is to drink a lot of water, to use an small pump atomizer that you can refill. Wetting your hair as it can retain water is also a good solution.

hetspookjee 5y ago
The smell will come later. I'd recommend washing the shirt after a day to remove the bad smell. The 10 min is in the full sun while exercising. Sitting behind a desk in a closed environment I'm able to wear it for ±1-2 hours with effective cooling. If the shirt is dripping water, it's too wet and you should press out the water more. Also a thicker cotton feels less comfortable in my opinion, I prefer to wear a thin one and wetten it more frequently!

Causality1 5y ago

If I jogged for ten minutes in 35c my shirt would be wetter than it was when I pulled it out of the sink. No sweat when facing >35 degrees inside. Why in the world would you have to deal with >35c inside? Do you do construction? Frequent power failures?

pjerem 5y ago
35°C inside can totally happen in a house or an apartment without AC and window shutters.
skrebbel 5y ago
I love that you simply cannot imagine that houses without air conditioning could exist. In a thread about the weather in Canada, even.
- Causality1 5y ago
  Having no AC because it rarely gets hot is like having no roof on your house because it never rains. It's a silly risk to take, especially when heat pump systems cool and heat the house equally well and much more efficiently than furnaces or resistive heaters.
  - skrebbel 5y ago
    I live in a developed country where, I estimate, less than 1% of houses have AC.
auxym 5y ago
Not sure about BC, buy here in Quebec, not everyone has AC. I mean, it's not that uncommon, but off the top of my head I'd head estimate that roughly a third of people have AC? Of course, when a heat wave comes, everyone wants to buy one of those windows or floor units, but then they sell out at every store in a few days. I don't have AC in our house, but we do ga e a basement that stays cool even in extreme heat. Not that fun living in a basement, but realistically the AC would only get used a few days a year in average.

monkeynotes 5y ago

The answer to climate change is to wet a t-shirt and sit next to a fan in your damp armchair while watching the world burn. Talk about frog in a pot.

recursive 5y ago
At least it's something that can be done.
EForEndeavour 5y ago
Why equate a clever tactic for instant relief for an individual stuck in a potentially fatal heat wave with "the answer to climate change"? Does the inexorable rise in atmospheric CO2 somehow make it unacceptable for a person to seek relief from heat?
- monkeynotes 5y ago
  It was really a flippant comment on the state of the world today. I think it's still relevant. We are dealing with the affects very well, but not the cause. This is typical of how humans function and worth pointing out if only for gallows/morbid humour.
missedthecue 5y ago
According to Lancet, extreme cold kills 20x more people than extreme heat every year. As summers get hotter and winters become milder, fewer humans will die on account of extreme temperatures.
- EForEndeavour 5y ago
  Got a link to the source for that ratio? Also, your conclusion definitely doesn't follow from that ratio alone. A simple example: Before: cold kills 20 people, heat kills 1 person. Cold kills 20x more, for a total of 21 deaths. After: cold kills 15 people, heat kills 15 people. Cold kills the same number of people as heat, for a total of 30 deaths.

tomcooks 5y ago

Why not wet a kiffeya or a scarf and wrap it around your neck? Cools you faster

hetspookjee 5y ago
You could do both =). Make all your clothes wet and let adiabatic cooling do it's work for you

bb101 5y ago

You can also buy ice packs that you wear draped around your neck. It cools the blood flowing to your cartoid artery, along with the general area. Works really well.

truenamenofame 5y ago

I have to deal with this problem living in a room with no AC/central air and I have some tips that may be useful for others in the same situation. 1. Put a frozen water bottle under your shirt. Keep backups in the freezer to cycle from. It seriously feels amazing and sucks the heat out of your body. 2. Use two or more fans, one good one to blow air at yourself and another one that is redirecting hot air away from you (so it's facing somewhere away from you). It's just like how airflow in a computer works I guess lol 3. Have ice always available, drink a ton of ice water and stay hydrated. The difference between doing these things and not doing these things for me is having a somewhat productive day vs spending the whole day doing nothing.

jonpurdy 5y ago

This works extremely well on a motorcycle at any speed above 20 km/h, even under protective gear (the only way I've tested). So well that I actually feel a bit cold at first when it's hot but not extreme (below 30°C).

pvaldes 5y ago

Exact. And a similar trick can be used with a bed sheet hanging extended in rope for cooling your bedroom in very hot nights.

mark_l_watson 5y ago

I live in the mountains of Central Arizona, and I do something similar. On really hot summer days, I will take a 45 second cold shower ever few hours. Probably not so healthy to shock the body, but it helps with the heat. About ten years ago we installed solar panels so now air conditioning is basically free during the day, but I still like the ice cold showers.