Heat is energy too
Heat is a kind of energy. The greatest natural source of heat and light is the Sun. Artificial sources: fire, cooker, heater, electric kettle. Heat passes from a hot object to a colder one. If we rub our palms together they warm up: motion energy turns into heat. Clothes do not heat us: our body warms itself and clothes help keep the heat in. Temperature shows how hot or cold something is. We measure it with a thermometer in degrees Celsius (°C). Water freezes at 0 °C and boils at 100 °C; a healthy person’s body temperature is about 36.6 °C.
Experiment: 1) Rub your palms hard for 10 seconds and feel them warm up. 2) With a thermometer measure the temperature of the room, the outdoors and cold water and write it in your notebook. Which is the coldest? Safety: use only an alcohol or electronic thermometer (not mercury); do not work with boiling water, use warm and cold water.