Why is fire so hot?

Answer

Dear Reuben,

Heat is nothing but energy from moving particles (atoms or molecules). The more and faster the particles move, the hotter they are.

When the particles stop moving, the energy drops and so does the temperature.

Your skin will absorb some of the energy when you touch a hot object. The molecules in the cells of your skin start to move more and become warmer themselves.

The warmer the object you touch, the faster and more the molecules in your skin will move. Fortunately, you also have nerve cells that feel that energy and give the signal to your brain if too much energy (heat) reaches your skin. You can then normally protect yourself in time by, for example, pulling your hand away.

For your skin, there are different limits of heat that you can tolerate. For example, your normal temperature of your skin is about 36°C and you can easily tolerate temperatures of up to 42°C. Then it sometimes gets a bit too hot:

From about 42°C your first pain receptors will be stimulated and from 45°C all pain receptors will send a signal to your brain.

You can burn by being exposed to 44-45°C for several hours. (your skin will already look red)

From 47°C it takes less than an hour to burn yourself on the object.

From 55°C it only takes a minute to burn you.

Above 60°C you burn within a second (your skin will then look red, blisters will take a little longer)

With a temperature of about 400 to 600°C, fire is directly responsible for a burn.

Kind regards,