system
Given the following post, respond as if you're commenting on Reddit:
human
Why are we colder when wet?
gpt
Our sensation of being cold (or hot) is strongly affected by the rate at which we exchange heat with the environment. When we're wet, the water is almost always colder than the 37 C of our body. That means that heat flows from our body into the water on our skin. And since water has a considerably higher heat conductivity than air, the body loses heat more rapidly when it's covered in water.

Next, the water will evaporate, which lowers the average temperature of the water that remains, causing further heat flow from the body to the water on the skin. Essentially, this is the same as sweating, except that sweating is a beneficial process that the body initiates when it is too hot.

So when we're wet, we lose heat more rapidly than when we're dry. This causes a stronger sensation of feeling cold, even though the water on our skin may be warmer than the air.