Why does humidity in the heat make you feel hotter, but if you spray yourself with a fine mist of water in the heat, you feel cooler for a minute?
In: Earth Science
Your body cannot measure temperature. All it measures is heat flow. High humidity in the air allow it to transfer more heat into you, so you feel hotter. That’s the “feel like” thing that is in the weather report. If you mist yourself with water, evaporation of that water causes heat to flow from your body, so you feel cooler.
When the humidity is high, the water that evaporates just gets stuck in the air as a drop of water and doesn’t carry the heat away. The body is like a radiator. Your skin is one of the organs that helps regulate body temperature. Think about it this way, your skin is a radiator in two ways: you can have a warm radiator, or a cool radiator. If you take away the radiator fluid (sweat) your radiator (skin) will overheat. The mist of water on your skin is like adding radiator fluid.
You answered your own question. Evaporating water makes your skin feel cooler. Humidity slows evaporation. If there was no humidity at all and you got water on your skin (or just sweated) the water evaporating would cool you down a lot, but if the humidity was at 100% there would be barely any evaporation and the water would simply sit on your skin. Humidity is rarely 0% or 100% in the summer, so it’s a scale that feels worse and worse as it goes up
Also you have more molecules of a given temperature touching you with higher humidity. 90 degrees dry as an example feels way better than 90 degrees with more 90 degree molecules touching you. Add the lack of evaporative cooling and other factors and you have gross weather.
humidity prevents water from evaporating. water sprayed on yourself evaporates and cools you. if you sprayed water on yourself in high humidity you probably wouldnt feel much relief.
Imagine a glass of water with some sugar in it. If there’s already a lot of sugar dissolved in the water, it will be harder to dissolve more. Imagine if the act of dissolving sugar in water made the water cold, but once you have a lot of sugar dissolved, because it becomes harder to dissolve more, at a certain point you can’t keep the water cold.
When water turns from liquid to gas, whether by boiling or evaporation, it takes some heat with it. If there is a lot of water in the air, it is harder for more to evaporate, so your sweat just stays on you and can’t take the heat anywhere. If it’s not too humid and you put water on your body, it will then evaporate and take heat with it. Also, the water may be colder than the air temp, so that can also cool you.
Humidity in the heat makes you feel hotter because your sweat doesnt evaporate. The reason humans sweat to cool down is because the evaporation of the sweat makes us feel “cooler”
Being misted makes you feel cooler for a moment because the water is a lower temperature than your body, so it will feel nice until it heats up to whatever temperature you are at
Latest Answers