All over your body, you have receptors that send information to your brain about the environment. One type of those receptors can tell your brain how hot or cold something is… but what happens when those receptors become desensitized? Does your brain get mixed signals?
Question
Can you tell if something is hot or cold by touching it?
Materials
- 3 buckets or bowls
- Ice water
- Hot water (no more than 100°F)
- Room temperature water
What to Do
- Fill one container with ice water, one with room temperature water, and one with hot water and place them in a row.
- Have students hold one hand in the hot water and the other hand in the cold water.
- After one minute, have students place both hands in the room temperature water. What do they feel? Do both hands experience the same sensation?
What is Happening?
The receptors in our skin quickly become desensitized to repetitive sensory inputs. When we leave our hands in an uncomfortable (but not dangerous) warm or cold bath, the brain quickly begins to ignore the message and eventually begins to “reset” what is normal. When we switch baths, this “resetting” makes the new extreme feel much colder or hotter than it would if our hands had been kept at room temperature.
Activity add-ons:
What happens if you leave one hand in the cold and move the other hand directly from the hot water to the cold water after one minute?
What if you hold both hands in the hot water then place one hand in the room temperature water and the other in the cold water?