Wikipedia:Reference desk/Archives/Science/2019 July 28

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July 28

Drinks during the summer heat

I was recently in Austria during what was supposed to be a heat wave at the time (it rained pretty much every day) and a shop window said that to survive the heat wave, one should avoid drinking alcohol and drink lukewarm drinks instead of cold drinks. I can understand the avoid alcohol bit, but why lukewarm drinks instead of cold drinks? JIP | Talk 00:37, 28 July 2019 (UTC)

I don't understand it either: they also eat ice-cream don't they? If you were to buy them one, would they have refused it? Tgeorgescu (talk) 01:02, 28 July 2019 (UTC)

I think Austria was in the side of the omega-shaped thingy where it was past the cold front and maybe wind came from the north instead of Sahara. And Alps are good at blocking wind from Sahara if it did come from there. Thus heat stayed in Germania Occidental and BeneluxfranorwUKiberitaliswiss. German heat record was almost in Netherlands. Sagittarian Milky Way (talk) 01:35, 28 July 2019 (UTC)

Coverage of all three days of the 2019 Austrian Grand Prix mentioned that temps were hotter than usual. That track is the Red Bull Ring outside of Spielberg. Its elevation is 660 meters where normal temps are milder than that. Now this is just one city but I've read that the heat dome effected Austria as well. MarnetteD|Talk 04:17, 28 July 2019 (UTC)

A good reason I can think of is that drinking water gets infected during hot summers. But of course this has nothing to do with bottled soft drinks. Tgeorgescu (talk) 05:07, 28 July 2019 (UTC)

The explanation I was given as a kid is that very cold drinks shock your body and cause it to work extra to heat itself up and avoid hypothermia, which counteracts the cooling effect from the drink. Tho even if it's true it's probably a very minor effect. Nobody gets fat just from eating hot food :-D 93.136.43.218 (talk) 05:41, 28 July 2019 (UTC)

Physically, evaporation is what cools you. Drinking lukewarm or even hot will make you sweat more quickly. Drinking too cold will trigger cold-defense mechanism: vasoconstriction, production of more heat (even goose bumps). Obviously not the objective.

And, drinking alcohol will also cools you actually, because of vasodilatation. However, if you are already struggling against heat, your peripheral blood vessels are already dilated, and an extra vasodilatation stimulus will do no good, and could even induce vasodilatory shock or reflex syncope if you drink too much (disclaimer: no need to be alarmed, but some awareness required, as those effects could be both just funny and in rare case dangerous and even deadly. No medical advice etc.).

Gem fr (talk) 11:00, 28 July 2019 (UTC)

I recall that during the running boom of the 1970s, there was a theory that lukewarm drinks were absorbed more quickly than cold ones, but that seems to have fallen by the wayside long since. The only thing I can find on the net now seems to state the opposite... "Contrary to what you have heard, cold drinks are not absorbed into your body more quickly than warm ones. However, cold drinks are often more palatable than warm ones during exercise, so if coldness helps you to drink large quantities of fluid while you exert yourself, then keep your drinks cool.". [1] Alansplodge (talk) 17:51, 28 July 2019 (UTC)

A bit more Googling found: "The American College of Sports Medicine recommends that athletes start drinking soon after commencing an exercise and continue drinking at regular intervals to help replace fluids lost during exercise. The College recommends that fluids be cooler than the ambient temperature, but they do not recommend icy or frozen beverages". See Should an Athlete Drink Cold or Warm Water?. Alansplodge (talk) 17:57, 28 July 2019 (UTC)

Just from personal experience, drinking or jumping into cold water has only ever felt like a big mistake after I was already overheated. When staying cool to survive, both have always felt about right. Hot water on frozen skin likewise hurts shockingly more as a cure than a prevention. InedibleHulk (talk) 18:16, 28 July 2019 (UTC)

I would expect that the best option is to slowly sip water as cold as you can get it. The cold water will lower the body temperature, while sipping it will ensure that it isn't lowered so quickly that your body feels the need to generate heat by shivering, etc. Of course, as a practical matter, keeping cold water cold isn't always easy. You can put ice in it, and keep it in a thermos, which will make it last longer. SinisterLefty (talk) 20:04, 28 July 2019 (UTC)

In the Netherlands the common wisdom is that ice-cream sales are skyrocketing during hot days. If that were dangerous, we would hear about lots of dead people because of eating ice-cream. The explanation which I find compelling is that the functioning of internal organs produces redundant heat, which has to be disposed of anyway. Tgeorgescu (talk) 00:29, 29 July 2019 (UTC)

Ice cream might not cool you down as fast as a cold drink, because you consume it slower, due to eating with a spoon versus guzzling, and brain freeze limiting even that. SinisterLefty (talk) 00:36, 29 July 2019 (UTC)

Ice cream is not a very good way of re-hydrating. Alansplodge (talk) 18:03, 31 July 2019 (UTC)

It would be an interesting challenge to make an ice cream that was. It might end up being more like a Gatorade slushie, but perhaps you could add pureed frozen bananas to give it a creamier texture and also provide potassium. SinisterLefty (talk) 18:46, 31 July 2019 (UTC)

While you should drink enough, it's more efficient to put water on your clothing and get evaporative cooling that way, instead of your body having to process the water, convert part of it to sweat to provide for that evaporative cooling. Count Iblis (talk) 01:22, 1 August 2019 (UTC)

I've tried that method myself. I have a pair of leaky hip flasks that slowly drain ice-water in my front pockets and down my pant legs. But I would only use this as a last resort, since it looks bad, can be uncomfortable if I sit in wet pants, and could get the chair wet, and obviously I can't carry anything in those pockets that can't get wet. But if I'm facing heat stroke, I'd do it again. SinisterLefty (talk) 01:59, 1 August 2019 (UTC)

Sounds like a recipe for Chafing (skin). Alansplodge (talk) 18:09, 1 August 2019 (UTC)

Not really. My skin would be wet from sweating anyway, if I didn't do this. But this way I don't get dehydrated from sweating so much.SinisterLefty (talk) 20:29, 3 August 2019 (UTC)

People tend to sip slowly at very cold drinks. Many people can consume water faster if it's slightly warmer. In very hot weather, all that matters is how much water you drink, not the temperature of the water. If someone is dehydrated, it's better to give them water at a temperature that they can consume fast rather than ice-cold water that hurts to drink. In very hot weather this is largely moot - drinks heat up fast enough that it's not hard to stay ahead of the hydration curve. Charles Randles (talk) 14:58, 3 August 2019 (UTC)

Sleep deprivation

Can sleep deprivation directly cause death? Putting aside people dying from the effects of sleep deprivation, (i.e driving with impaired motor function, etc) can the lack of sleep itself actually kill you? If so, how long would it take? A week, two weeks, a month? Is it even possible, or would you automatically fall asleep if you were that tired? --Puzzledvegetable^{Is it teatime already?} 15:31, 28 July 2019 (UTC)

We have some information about longest periods without sleep at Sleep deprivation#Longest periods without sleep but I can't tell how directly it is Fatal insomnia that causes death in certain cases. DMacks (talk) 15:37, 28 July 2019 (UTC)

It is a prion disease of the brain.. It cause both insomnia and death, insomnia being a side effect, not the cause of death. Gem fr (talk) 16:11, 28 July 2019 (UTC)

I guess you don't understand "directly" as, say, "so tired he fell asleep when driving, causing a fatal accident", which by far more likely too occur than anything else related to sleep deprivation

As far as we know, quite a number of psychopath not afraid to kill people tried sleep deprivation on others to see what effects it would have, and they didn't observed death. Death occurs when a vital organ stops. All of them work whether you are asleep or not, obviously, and do not require sleep. However, endocrine system has some effect on them, and sleep has some effect on the endocrine system. So sleep deprivation could change the probability of a failure (a stroke, or a heart failure, for instance), but if such effect exist, it is difficult to see, and would not be "direct". Gem fr (talk) 16:11, 28 July 2019 (UTC)

Careful with the mansplaining. You made a ton of unsupported medical and other claims, which are all contrary to how we should be responding to questions here. See doi:10.1093/sleep/12.1.1 for animal study (and refs to others) on possible causal relationship of sleep-deprivation leading to death. But obviously one can argue (and the article makes the statement) that it's not proveable that "lack of sleep" itself directly caused death, vs intermediate stages and involved systems. So perhaps the question itself is meaningless. DMacks (talk) 16:29, 28 July 2019 (UTC)

For a stark look at the consequences of sleep deprivation, see Fatal familial insomnia. Oops, I see someone already linked to that. There's a distinction to be made between "normal" sleep deprivation and the inability to sleep, which is ultimately fatal. ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:42, 28 July 2019 (UTC)

Be careful. In Fatal familial insomnia, sleep deprivation is NOT the cause of death, the cause of death is brain damage (encephalopathy) caused by a prion similar to Creutzfeldt–Jakob disease or Mad cow disease. Sleep deprivation is one of the early onset symptoms of the disease, NOT the cause of death. --Jayron32 15:56, 29 July 2019 (UTC)

Fatal insomnia which as pointed out here does not cause death by sleep deprivation, can be used to put limits on the negative effects of sleep deprivation. People die from brain damage caused by the disease which takes many months, which means that the sleep deprivation factor alone cannot cause death on a time scale of less than a few months even in case of people with this horrible disease. Count Iblis (talk) 17:58, 29 July 2019 (UTC)