From the Mayo Clinic: (retrieved from the internet 10/1/2012 by MadelineB)
Hypothyroidism (underactive thyroid)By Mayo Clinic Staff
Hypothyroidism (underactive thyroid) is a condition in which your thyroid gland doesn't produce enough of certain important hormones.
Women, especially those older than age 50, are more likely to have hypothyroidism. Hypothyroidism upsets the normal balance of chemical reactions in your body.
At first, you may barely notice the symptoms of hypothyroidism, such as fatigue and sluggishness, or you may simply attribute them to getting older. But as your metabolism continues to slow, you may develop more obvious signs and symptoms. Hypothyroidism signs and symptoms may include:
Fatigue
Sluggishness
Increased sensitivity to cold...-----------
Maddie note:
Three of the women in my immediate family are treated for hypothyroidism. Consistent low core temperature was the symptom that clinched it for the doctors, who then put each on inexpensive levothyroxine and their conditions improved.
Be aware that making one's internal chemistry female may also increase ones chances of developing hypothyroidism.