system
Given the following post, respond as if you're commenting on Reddit:
human
How does your body 'know' when to give you a fever?

When you get a common cold, you don't get a fever. When you get the flu, you often do to kill the virus in your system. What determines whether your body goes into a fever or not and how does it know when to do it?
gpt
The immune system produces many types of inflammatory mediators. One class of mediators is called Interleukins. Of these, IL-1 and IL-6 have an effect on the hypothalamus causing the body to reset the temperature higher. This is what causes fevers.