Why are people prone to fever when they are cold (scientific answer)

People do not necessarily have a fever after catching a cold.

Only when you are sick will you have a fever.

What you need to solve is why people get sick easily after catching cold.

There is a theory that when the weather is cold, the resistance of epithelial cells of respiratory mucosa decreases, and bacteria or viruses that originally existed in the respiratory tract will invade the body and get sick.

Most people will get "respiratory infection" diseases after catching a cold, such as "cold" and "tonsillitis". You won't get gastric ulcer because of a cold. )