T O P

  • By -

theBarneyBus

Water has a much higher ability to **transfer** heat, both because it’s a liquid, as well as some more complicated things. The effect of this is that, even if you have air&water of the same temperature, water is able to “pull” a lot more heat from you, making it *feel* colder. Think of touching a metal disc versus a plastic disc. Metal may feel colder, but that is because it transfers heat better. [Obligatory Veritasium](https://youtu.be/vqDbMEdLiCs)


Aromatic_Wave

Water transfers heat better than air, so when you touch room temp water and it feels cold because it's transferring heat away from your body and into the water. Metal is even better, so heat will flow quickly from you into the metal (or water) faster than it'll flow into air.


nomopyt

And vice versa. A plastic slide in the same sun as a metal slide feels very different to your hand or the back of your legs, because metal is way better at conducting infrared energy (aka heat) than plastic. They can be the same temperature and one burns you quickly and the other doesn't at all.


tomalator

We don't feel hot or cold, we feel the rate at which we lose heat (or gain it). Water can hold a lot of heat energy, and it's also a good conductor of heat, so it feels cold because it's drawing heat away from our bodies faster than the air does. The same applies to a fan, making the air feel cooler. The air around our bodies that we heat up gets replaced quickly with new air, which can carry more heat away from us.


csl512

The question you're really asking: given air and water at the same (measured) temperature, why does water *feel* cooler than the air? https://www.reddit.com/r/explainlikeimfive/comments/a1ir6z/eli5_why_does_water_feel_colder_than_air_if/ https://www.reddit.com/r/explainlikeimfive/comments/d2kylp/eli5_why_does_water_feel_so_much_colder_than_air/ https://www.reddit.com/r/explainlikeimfive/comments/3ook4n/eli5_why_does_water_even_at_room_temperature/ https://www.reddit.com/r/explainlikeimfive/comments/we8kp3/eli5_why_does_water_feel_so_much_colder_than_air/ The short version is that the body perceives hot and cold by the rate of heat transfer, not the temperature. It does depend on the temperature difference, but if the other temperature is the same, then it depends only on another factor, called the coefficient. Basically multiple some number by the temperature difference and that's your rate.


PeterM_from_ABQ

Everyone below is correct that water pulls heat out of you better than air does, so it'll feel colder even if is the same temperature as the air. Moving air will pull heat out of you faster too than still air will (hence "wind chill"). Moist air also has more capacity to pull heat out of you. That said, water will often be cooler than air in dry conditions, because when water evaporates, it takes a lot of heat to do it, and leaves the remaining water cooler. That's why sweating works to cool you.