Heat is a type of energy that makes things hot. If there is a lot of heat in one object, the object will be hot. If there is not much heat in something, it will feel cold
For example, this stove/oven is heated to 350 Degrees Fahrenheit, or 177 Degrees Celsius. If you add more heat, the temperature will go up. it you take away heat, the temperature will go down.
How do you know how much heat there is in an object.
You can use a thermometer. A thermometer has Mercury in the middle, and it rises in the thermometer until it reaches the temperature it will go to. If the mercury is high in the thermometer, and it goes in something cold, it will go lower. If there is a lot of heat in something, the Mercury will go high in the thermometer, and if there isn't a lot of heat in something, the mercury will stay close to the bottom of the thermometer.
For example, if i put the thermometer in boiling water, it might show that it is at 212 Degrees Fahrenheit or 100 Degrees Celsius because there is alot of heat in Boiling water. if i put in in snow, since there is very little heat, the temperature might be 32 Degrees Fahrenheit, or 0 Degrees Celsius.