 
It was very hot on the day we visited the park, so we spent some time at the water park and wave pool. Here we noticed an interesting phenomenon.No, not the tattoo! The pool water is much cooler than the air. One would expect that when you get out of the pool, you would immediately start to feel hot again, in the bright sun and warm air. However, what actually happens is that, despite the heat, everyone who gets out of the pool immediately begins to shiver! Why would you shiver when the outside air temperature is over 90°F, or 32°C? Here's the reason. Your body is coated with a layer of water, which quickly begins to evaporate. In order for this liquid to change to a gas, it must get a lot of energy from somewhere. Gas particles have much more energy than liquid particles. Some of the energy that goes into the water particles is drawn from your skin. As the heat leaves your skin and turns the water to gas, your skin becomes cooler. As a liquid evaporates, it steals heat from the surface it was on, making that surface cooler. This is exactly the reason why you sweat. Persperation is a liquid; as it evaporates, your skin gets cooled. Find out about other ways your body can be cooled here. This process creates other problems, however. Your body uses liquids for many purposes; the main use is to transport food and oxygen around your body, using blood. Ordinarily, this liquid doesn't get lost ... it stays inside the body. But your body must use some of this water to cool itself, by sweating. It also must use some to flush out poisons, by dissolving them in water, which you then eliminate as urine. Both of these processes cause water to be lost from the body. That's why you need to continually consume more liquid. |