Everyone is different, and we all know what's correct for our own individual body temperature. But even 100 isn't really high, per se. Temperatures of 101-102 need to be monitored. Generally speaking, 103-104 and above needs to be watched very closely, and 104 -107 fall within the danger zone. Efforts need to be taken to reduce temperatures that high. (A doctor told me this a few years ago. It's a very general guideline only, keeping in mind the plethora of so many other important factors such as age, other compromising medical issues per individual, current medications, etc.) Lower fevers are the body's natural response to help you fight infections, and I've heard debates about whether the (lower) ones should just be left alone, and run their course.