### Theory:

Flow of Heat
The flow of heat is the process in which energy is (thermal energy) transferred from one object to another. Generally, the heat is transferred from the hotter object to the colder object. Temperature determines the direction of heat flow.
Example:
1.  Heat transfer between a cup of coffee and hand.

You are holding a cup of coffee

Would the heat energy transfer
1. From your body to the coffee, or
2. From the coffee to your body?
The heat will transfer from the cup of coffee to the hand.

It is because the temperature of your body (hand) is lesser than the cup of coffee.

Hot object - the cup of coffee
Cold object - the hand

We know that heat is transferred from a hot object to a cold object. In this case, heat is transferred from the coffee to your body.

2. Heat transfer between air particles and the human body.

You are standing outside on a summer day. It is $$40$$°$$C$$ outside. Would the heat energy transfer from,
1. Your body to the air particles, or
2. The air particles to your body?
We know that the normal body temperature of a human body is $$37$$°$$C$$. In this case,

Hot object - Air particles ($$40$$°$$C$$)

Cold object - Human body ($$37$$°$$C$$)

Here, heat will transfer from the air particles to the human body.

3. Heat transfer between the air particles and the human body.

You are standing outside on a winter day. It is $$23$$°$$C$$  outside. Would the heat energy transfer from,

1. Your body to the air particles, or
2.
3. The air particles to your body?
4.

We know that the normal body temperature of a human body is $$37$$°$$C$$. In this case,

Hot object - Human body ($$37$$°$$C$$)

Cold object - Air particles ($$23$$°$$C$$

Here, heat will transfer from the human body to the air particles.
Reference:
https://photostockeditor.com/image/person-man-looking-at-snow-mountain-snow-69043