# Breaking a fever (Physiology question)

**URL:** https://boards.straightdope.com/t/breaking-a-fever-physiology-question/503436
**Category:** Factual Questions
**Created:** [July 18, 2009, 2:46pm UTC](https://boards.straightdope.com/t/breaking-a-fever-physiology-question/503436 "2009-07-18T14:46:13Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)
#### Post date: [July 18, 2009, 2:46pm UTC](https://boards.straightdope.com/t/breaking-a-fever-physiology-question/503436/1 "2009-07-18T14:46:13Z")

</div>

When I’ve been sick, I’ll feel like crap. Then one night I’ll go to bed, and sometime during the night I’ll wake up in a sweat and I’ll be fine. It’s a common trope in film and television, where someone is sick and the drama builds as no one knows id the person will live or die; and then the fever ‘breaks’, the person is covered in sweat, and s/he’s on the mend.

So physiologically, what exactly is going on? I understand that a fever is the body’s way of fighting the illness. I understand that sweating is the body’s way of cooling off. So it’s like the body is saying ‘I’ve got to warm up! No, wait. I have to cool down!’ I’ve always been asleep when this happens. Does the cool-down (sweating) occur after the body has determined that it has won the fight? Or is it concurrent? And if it’s concurrent, why?