'Heat' is a verb or noun. As a verb: "I am going to heat my supper up as it was too cold". (I'm going to make my supper warm) As a noun: "It was 40C today and the heat (high temperature) was killing the flowers. 'Hot' is an adjective I feel very hot If you heat up the soup too much, it will be too hot. (heat as a verb, hot as an adjective)

Things give off heat which makes themselves, the environment or ourselves hot. For example, • Fire gives off heat, which makes it hot. • The heat (that the sun is giving) is making me feel hot. • Heat is coming from my laptop, so the keyboard is hot.

Heat is a measure of energy, hot is a subjective term and is usually used when an object has a significantly higher temperature than other objects in an environment (boiling water in a cold room for example)