Why does my body temperature keep fluctuating? Is it the female hormones?

Could be. In perimenopause and menopause, the thermostat for women seems to be "reset". Small changes in the ambient temperature, spicy foods, stress, or wine may trigger hot flashes. On the other hand, other medical problems such as thyroid dysfunction, infections, or lymphoma, can also trigger temperature fluctuations, so check with your doctor if you are too young or too old for menopause.