Sweating Is Triggered

• Your average body temperature is 98.6 degrees F, but if you do something to raise this temperature, such as exercising or going out on a hot day, your body begins to take counteractive measures. The hypothalmus gland in the brain detects a rise in body temperature and responds by triggering the skin pores to begin to produce sweat. As it accumulates, it is released from the skin pores to the surface.
  
  

What Sweat Is Made from and What It Does

• Sweat is mainly water with a combination of urea, salts, ammonia and sugars. This is why when you sweat a lot, you need to replenish not only lost water but lost minerals such as sodium and potassium as well. Sports drinks include these in their formulations to help sweaty athletes to recover. The water in sweat turns to a gas in the air; this process is known as evaporation.
  
  

Water to Gas Conversion to Cool You Down

• As the molecules of water change into a gas, they can float away from the body. When sweat evaporates and becomes a gas, it not only changes its state, but it also takes a small amount of heat with it when it floats away from your body. Multiply this by millions of sweat molecules, and your body begins to feel cooler. The sweat literally takes the heat away from your body.
  
  

Barriers to Evaporative Cooling Through Sweat

• Sweat will only evaporate into air that is not already saturated with water. If you are in a very humid area, your sweat will not evaporate as much because the air cannot allow for any more water molecules in it. The more you sweat, the more humidity the air near your skin will have--even in drier climates. By standing in a breeze or fanning yourself, you can move that humid air out of the way and evaporate more of your sweat, thereby further cooling your body.