ELI5- When you’re really thirsty, and drink warm water – it doesn’t feel good. But when you drink cold water- it feels like heaven. Why?

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I had kept my metal bottle in the car which was parked in sunlight for long hours. I got into the car and I was parched so I drank that warm ass water and it didn’t feel good and it took me 7-8 big sips to actually feel like i drank any water.

In: Chemistry

16 Answers

Anonymous 0 Comments

Not an expert, but I assume your body makes you drink water to increase sweating to cool you down. Drinking warm water before sweat can start cooling you down might make your body think the water you drank had no effect.

Meanwhile, cold water instantly lowers your body temp. Your brain can tell your body feels immediately cooler due to the coldness of the water and that makes you feel instantly satisfied.

Anonymous 0 Comments

Think about the primary scenario in which you are significantly thirsty: right after exercising or enduring high temperatures, i.e. right after you’ve been sweating a lot and you’re running low on water for thermoregulation. Now picture your mouth, which is absolutely PACKED with blood vessels (which most mammals including your distant ancestors used to pant to relieve heat).

Cold water cools you down AND hydrates you. Warm water only does the latter. Is it any wonder why you associate the coldness with pleasant feelings, and therefore enjoy the sensation of cold water more than warm water? Even if you aren’t hot, you still remember times you were hot and drank cool water, and so your preference stays.

Also, as a minor secondary effect: warm water evaporates any dissolved volatile compounds more efficiently (so you smell any impurities slightly more strongly) while cold water can make your taste buds momentarily less sensitive (so you taste impurities less).

Anonymous 0 Comments

There are a few factors but lets think about it from a biology side.

Imagine you’re out in the wild. You come across a shallow pool in the sun. Its warm. What is your brain telling you. This is old water, it has been sat stagnant in the sun for a long time. This water is not ideal.

Where is water going to be super cold? Running streams. What is your body telling you about that when its cold? Its fresh, its safe, drink more.

Anonymous 0 Comments

Cultural expectation. Drinking cold water for relief from thirst is not universal. In China for example they would drink warm water in this situation.

Basically the culture you are from promotes cold drinks for thirst quenching, so you have come to associate that sensation with quenching.

Anonymous 0 Comments

You probably have basically unlimited access to clean drinking water. That means you’ve probably never experienced being thirsty from actual lack of water.

You’re usually really thirsty when you’re hot. That’s because your body lets go of tons of moisture when you’re hot (in the form of sweat).

Your body doesn’t like being heated up when it’s trying to cool down. The whole reason it wants water is to sweat and cool off. Putting warm or hot water in your body at that moment is counter-productive.

However, warm water can feel good if you are thirsty and cold.

Anonymous 0 Comments

When something is colder the taste is less acute so if you drink warm water the taste isn’t as clean, crisp and clear

Anonymous 0 Comments

I’m the complete opposite on this. I hate cold water when I’m really thirsty. I want to chug the stuff as quickly as I can, and cold water kind of hurts (for lack of a better description).

I’ll sometimes keep water with ice on my desk at work for sipping on throughout the day, but when I’m really thirsty I want it to be room temperature.

Anonymous 0 Comments

Just going to throw out that dehydration is much different than thirst. If you are severely dehydrated ANY water tastes amazing. Especially that half bottle of water that was sitting in my car all day while I was at Warped Tour in 2005 and thought that the cost of water at the 11 hour event was too outrageous even though it was 95 degrees and sunny. That was the best tasting water I ever remember having.

Anonymous 0 Comments

Okay, everyone in the comments, repeat after me:

Drinking cold water is not a sustainable or efficient way to cool your body down.

Cold water doesn’t make you sweat, which is the long term cool down system run by our bodies. You sweat from hot, not cold. Your blood vessels expand from hot, not cold. If you want to cool down, (without applying a temperature to your skin), you drink warm liquids.

That’s why people drinking alcohol die easier in winter – blood vessels open -> body cools down too much.
That’s why when you’re sick, you stay covered and drink hot drinks, to sweat it out.

Hot=sweating=body cooling down.

Now to answer OP’ question:
It’s cultural. Depends where you were raised. You were cold drinks for the majority of your life, that’s what you’re used to. The more east you go, the more common is drinking room temp/warm liquids for hydration. We can chug a bottle of luke warm water, and it gives us the same relief and hydration, as if tou chug a bottle of cold water.

If it was safety thing, y’all would also drink hot drinks only. That was most cultures’ way to make sure they wouldn’t die from drinking random water. Make water hot – kill everything in it.

Anonymous 0 Comments

Warm water is disgusting?

Also cold water hides bad tastes and is universally loved.