RE: Body Temperature

Why is the body temperature of humans so high compared to our
surrounding environments temperature?

Humans are endotherms: animals which regulate their body temperature
using physiological methods to maintain a fairly constant internal
temperature. Endotherms have at least two types of advantages over
ectotherms (animals in which body temperature varies to a fair degree
with environmental temperature). 

First, endotherms can be active much of the time; thus they have more time
to search for food, mates, nest sites, and so on, than do ectotherms. 
Second, many biochemical pathways, and the enzymes which catalyze
them, reach maximum efficiency at temperatures in the mid thirties (that is,
at about 35 degrees C). This gives endotherms another advantage over
ectotherms. The disadvantage is that endotherms expend a lot of energy
just keeping their body at the correct temperature: cooling it when the 
environment is hot, and warming it when the environment is cold. A small
mammal may use 30 times, or more, the energy of a reptile of similar size.

All these points apply to humans, as much as to other endotherms, and the
temperature of many other endotherms is similar to the human temperature
of 37 degrees C.