Its great you work out so much...most people dont get the exercise they need. Actually, its somewhat normal to have a slight elevated temperature after a work out, especially a vigorous one as you describe. When a person exersices, their body's metabolism (how quickly it runs and how fast it burns energy) is raised. That increase in metabolic activity raises the bodys temperature because everything is going a little faster. The slight extra heat helps to power the bodies increased activities, and generally goes away after aboout 11 hours.
Information for this came from:
J. S. J. Haight and W. R. Keatinge (1973). Elevation in set point for body temperature regulation after prolonged exercise. Journal of Physiology, 229(1): 77-85.
Hope this helps...
As said before, it is normal to run a low grade fever after excercise. Have you overdone it? Thats something you would know far better than I..as it is your body. How do you feel? If you are feeling wretched, perhaps you can ease up a little...a baby takes baby steps before she can walk....a training program will also start small and build upon itself as the person gains more endurance. Also, remember to drink alot of water since you excercise alot. Not drinking enough can make dehydrate you.
Hope that helps,