Why do people tremble in cold weather?

In winter, the temperature is very low. When we go out, if we wear less clothes, we will often be shivering with cold. So why do people tremble?

shivering is actually a function of the internal control system of the human body. We have a brain tissue responsible for controlling body temperature-hypothalamus. Shivering is a way for the hypothalamus to keep the body at a constant temperature. When the body gets cold, shivering can make the body release heat and keep our body temperature in a relatively stable range.

people often tremble when they have a fever. This is because the hypothalamus raises the body temperature, thus trying to kill harmful bacteria. Here's how the process works: the subcutaneous blood vessels close to the skin contract, while other blood vessels relax, allowing blood to flow to the infected site. In order to supplement calories, the thyroid gland secretes hormones to make muscles contract, which makes the body tremble.

if people are frightened, they may also tremble. For example, when you come home from an evening movie, suddenly someone comes out of an alley, and you may be scared. At this time, your body will secrete adrenaline, leaving your muscles in a state of high tension. In a state of panic, blood will flow away from the surface of the skin, which is very similar to the state when the body is cold, so our body will start to tremble.