FAQ - What are normal temperature range?
Because of the level of variation in temperature between people, there are no 'normal' temperatures - rather there are average and typical temperatures which depend on the activity.
A typical resting core body temperature range for a human being is between 36.1°C / 97°F and 37.2°C / 99°F.
During the day, the temperature fluctuates and this is known as the Circadian Rhythm so the widely regarded temperature of 36.9ºC / 98.4ºF is a daily average and subject to variation. While sleeping the temperature will drop slightly and during the day it will rise.
During sport, the core body temperature can increase above 38ºC / 100.4ºF
Temperatures above 39ºC / 102ºF start to put the human body at risk of heat-stress although the training and conditioning of each individual means that the tolerance varies significantly. Our observations of elite athletes have shown top thresholds in competition range between 38.5ºC - 41ºC / 101.3ºF - 105.8ºF and suggest that athletes who monitor their own core body temperature will have a significant advantage in training and competition.
As a generalization, an athletic / trained person commonly operate better when hotter however optimal temperature and thresholds can still vary substantially.