Materials Required:
l Bathroom scale
l Paper and pencil
A hot summer day
Procedure:
- On a hot summer day, weigh yourself on the bathroom scale. Write down your weight on a piece of paper.
- Now go outside and play—ride your bicycle, play baseball, run. If you get thirsty do not come inside for a drink. Continue your play for at least a half hour.
- Next, return inside and get back on the scale. What do you notice? You probably weigh less than you did a half hour ago. Can you explain this weight loss?
This Is What Happens:
You may have recorded a difference in weight of as many as several kilograms. Most of this weight loss is water. Where did it go? To keep you cool while you were playing, your body produced sweat. When the sweat evaporates into the air, it takes away excess heat from your body. You probably notice that you drink many more liquids during the summer than during the winter months. You do this to replace the water that is lost through your skin. Otherwise, you would dry up like a withered plant! Now go have a nice, tall, cool glass of water and thank your body for keeping you cool—and letting you know it was thirsty.
