Re: What makes us shiver?

Hi Michael,

People shiver when they get cold, but you knew that I'm sure. The reason they do that is that the muscles are really pretty bad at using their energy (from food) into what they are good for (movement). A lot of that energy isn't used for moving your body, instead it is let go as heat. That is why you get really hot when you go running. You are moving around a lot, your muscles let off a lot of heat, and you get hot.

When you are cold however, you body is very smart and uses this mistake to its advantage. So here is what happens:

1. A part of your brain, called the hypothalamus, gets cold. It doesn't have to get very cold, just a little bit will be enough.
2. This part of your brain then makes your muscles shake. This way your muscles are moving, but you aren't running around. It works well.
3. This muscle shaking (shivering) makes a LOT of heat, can be as much as 3x as without shivering. If it is really cold, you won't be able to stop the shivering until you get inside and warm.
4. This warms you up, and your hypothalamus. After a while you stop shivering.
5. Of course if you stay in the cold, shivering may not give enough heat. In this case, your body temperature continues to drop which is very very dangerous. This is called hypothermia as is very bad and people have died of it.

Well Michael, I hope this helped; write me if you have any questions,

Jose
MD/PhD Program
Gradurate Program in Neuroscience
University of Minnesota