Why fever makes you hot and chilling?

When you have a fever, your body's thermostat is set higher than normal. This causes your body to heat up in an attempt to kill off invading bacteria or viruses. As your body temperature rises, you may experience a variety of symptoms, including sweating, chills, and a rapid heart rate.

Sweating helps to cool your body down by evaporating sweat from your skin. Chills are your body's way of trying to warm itself up. When you shiver, your muscles contract and relax, generating heat. A rapid heart rate helps to pump more blood throughout your body, bringing oxygen and nutrients to your cells and helping to fight off infection.

In most cases, fever is a normal and healthy response to illness. However, high fever can sometimes be dangerous, especially for young children and the elderly. If your fever reaches 104 degrees Fahrenheit (40 degrees Celsius) or higher, you should seek medical attention.