Dear Marcelina,

Lots of warm-blooded animals get sick, including cats. I’ve had a fever before, but I wasn’t entirely sure why we warm up when we get sick. I decided to ask my friend and professor Phil Mixter at Washington State University.

Mixter is curious about the germs, or microbes, that we all carry around with us. In fact, scientists estimate that humans carry more than 100 trillion of these tiny microbes with them wherever they go. Not all of these microbes are bad, but some of them can make you sick.

Thankfully, a lot of animals—from starfish to cats to humans—also have an … Continue reading Why do we get fevers?