WHAT YOU NEED
- spray bottle with water
- optional: humidifier or clothes steamer
WHAT YOU DO
Spray water on your arm and notice what happens. After a few minutes, it has evaporated and your arm is dry!
WHAT IS HAPPENING
On a dry day, your sweat evaporates into the air efficiently. As it evaporates, it takes some of the heat away from your body to go through that phase change from liquid to gas. Think about a humidifier or a clothes steamer. You put liquid water in, add heat (through electricity), and the water comes out as a gas instead of a liquid. On a humid day with lots of moisture in the atmosphere, your sweat cannot evaporate as efficiently so you can't cool as well.
DISCUSSION IDEAS
Do you notice feeling tired or sick on hot days?
Do you sweat as much in the winter as in the summer?
