Q: When you have a fever you either feel hot and shed clothing, or shiver and Doc tells you to take off excess clothing, but if you are shivering your body surely wants to be kept warm…?
Asked by ‘A. B. Cold’(!) via website
A high temperature is grim. It is little comfort to know that It is an entirely normal response to an infection. A fever is a bodily response from time immemorial – it is one of the most basic biological reactions to infection and has been passed down through our mammalian ancestors.
The principle behind a high temperature when unwell is to limit the growth of the bugs (bacteria, etc) that are invading the body. Many bacteria don’t reproduce as well at higher temperatures – so by increasing the core body temperature it gives the white blood cells a helping hand in killing off the aggressors.
A small region buried in the middle of the brain, called the hypothalamus, controls body temperature. Working just like a central heating thermostat, it is normally set to a steady 37 degrees C (or thereabouts). During an infection, it cranks up the dial (so to speak). To get the temperature higher, the body responds in the same way it would if in a cold environment: hairs stand on end, skin goes cold and pale, shivering. You also have the sensation of feeling cold.
Most fevers pass uneventfully and don’t usually need treatment in themselves. However, whether a fever really does much good or not to fight off the infection is unclear – it may be something we have inherited via evolution that doesn’t have much use. It’s by no means imperative that you ride through a fever to get better – staying cool may just help you feel a bit better.
Answered by Dr Stu