Does a fever always mean you have an infection?

The shivers, the shakes, the chills—we've all experienced a fever at one time or another. When we take our temperatures and the thermometer reads anything above 99 degrees, many of us immediately believe we are afflicted with some kind of infectious microbe. But, in fact, having a fever doesn't always signal infection. Yes, contagions like strep throat or the flu, are the most common reason for an elevated temperature, but it's surely not the only one. More uncommon ailments like brain inj