With so much strep, mono, colds, pharyngitis, laryngitis and flu going around, this has been a very busy flu season. One characteristic shared by all these infections is fever, a temperature > 100.4°F. But if we step back a moment to understand our immune system, we are forced to ask the question, “Are fevers really that bad?”
We have known for decades that both viruses and bacteria have optimal temperatures for reproducing. A team from Yale demonstrated that the cold virus spreads faster at lower temperatures (http://www.pnas.org/content/112/3/827), and even more interesting, the capsule of many viruses becomes harder and rubbery at lower temperatures making it more resistant to our immune defenses. We also know that most infectious bacteria are mesophiles, meaning they grow best between 68°F (20°C) – 104°F (40°C).
Enough with the science though. The take-home message is simple:
Our bodies mount fevers to help fight and slow the spread of infections.
Sure the extreme temperatures > 104°F need to be treated, but lower grade fevers may not be such a bad thing after all. Maybe next time I should take a clue from my wife next time she tells me to slow down with the Motrin.