Fever helps the body fight off viruses: But how does it work?

For centuries, the nature of a fever — and whether it's good or bad — has been hotly contested.

In ancient Greece, the physician Hippocrates thought that fever had useful qualities, and could cook an illness out of a patient. Later on, around the 18th century, many physicians regarded fever as a distinct illness, one that could actually cook the patient, and so should be treated.

These days, researchers understand that fever is part of the immune system's response to a pathogen, one that's shared by many animal species. And while there's accumulating evidence that fevers can help kick an infection, precisely how they can help remains mysterious.

"There's a cultural knowledge that there's this relationship between temperature and viruses, but at a molecular level, we're quite unsure ho