Core body temperature is the temperature of the internal organs that the body manages through the physiological processes of thermoregulation.  It is not a constant temp, as many people assume. It varies normally by a few degrees and can go as high as 104F during heavy exertion. High core temperature increases heart rate and puts a strain on the cardiovascular system, leading to decreased cardiovascular performance. In the extreme, elevated core temp leads to heat related illness and risk of serious injury or death. There are many valuable uses for continuous core body temperature monitoring.

Clinical

Infection and disease detection.  Monitoring sleep cycles and biorhythms.

Athletic Performance

Performance monitoring, training and safety. 

Occupational Safety

Heat illness detection.  For professions such as firefighters and soldiers.