For every two degrees Fahrenheit your temperature goes up, your heart rate increases ten percent. The good news is that there is a method to fever's madness.
Fever helps the body fight infection by revving up the immune system.
Once there, white blood cells called macrophages gobble up infectious organisms. Although higher body temperatures might kill some bacteria or viruses, fevers help us most by boosting the body's own immune response. Fevers are such valuable responses to infection that creatures all along the evolutionary scale get them. That includes friendly neighborhood dogs and cats, as well as critters you might not expect, like insects and lizards. In a lab, after a lizard is injected with live bacteria, it will creep under a heat lamp in order to raise its body temperature.