(The Best Years in Life) Is the average temperature of the human body still 98.6 (F)? This often quoted average was determined in the nineteenth century. A more recent study has reported an average temperature of 98.2, and many medical professionals believe this decrease in body heat is the result of an increasing prevalence of hypothyroidism. Whatever the answer is, one thing is sure. More people than ever are suffering from the large number of symptoms associated with low thyroid levels, especially women. Read More.