What Temperature Is It?

Different hands feel different temperatures..

 

 

 

Category - Our Senses 

Key Idea - Temperature

 

Purpose - Demonstrates that our nerves make judgments relative to other experiences.
Nature -  Demonstration with student participation
Materials -  3 plastic containers (such as empty ice-cream containers), access to hot and cold water, cloth for a blindfold
Method - 
  1. Blind fold one student
  2. Arrange the three containers next to each other in front of the student and fill the middle on with half hot and half cold water (to make about room temperature).
  3. Put hot water in the one to the students left, and cold water in the one to the students right.
  4. Place the students hands, one in the left most container and one in the right most.  Ask them which is the hot and which is the cold. 
  5. Leave the hands for a moment, then carefully place them both into the middle (room temperature) container.  Be careful that the students does not know that both their hands are in the same container.
  6. Ask them which in the hot and which is the cold, and you will find that they are very confused.
Safety - The hot water should not be so hot as to hurt the student.
Explanation - Our nerves work best when they respond to changes (which is why we can become numb to a feeling or smell after a while).  To the hand that has been in the cold water, the room temperature water feels very warm, and the reverse is true of the other hand.
Notes - Make sure that your student volunteer is comfortable with the idea of being blindfolded for an experiment.

This related to why swimming pool water sometimes feels so cold when you are very hot.  Your nerves are making a comparison with how they feel in the warm air temperature.