As a human being we fall ill with different kind of disease. Fever is one of the most common sickness in humans. But did you ever think how we get to know that we are having fever? No? When we don't feel good and it feels that we feel our body hotter than normal then we do check our body temperature with a device called, Thermometer. It tells what is the temperature of our body and if its around 100 degree F then we can say that we are in fever. So learn more about the temperature and thermometer in this video and enjoy physics learning in a new and fun way.