Just below the outer layer of the skin we have two types of temperature receptors. Hot receptors respond to things hotter than our skin and cold receptors respond to things colder than our skin. They are clustered together in hot spots and cold spots.

Try this experiment to see how these receptors work

You will need four beakers. Fill one with cold water, one with hot water (but not too hot!) and two with warm water ( both at the same temperature).

Put your left hand in the cold water and your right hand in the hot water for a minute. Now put both hands in the warm water.

What do you notice? What can you feel? Can you explain what is happening?