Hi
Welcome to the MedHelp forum!
Well, not all human beings have the perfect bookish body temperature. A person can have a ‘normal body temperature’ that would become lower in certain instances. Another person can have a lower temperature without any cause.
It also depends on what time you take the temperature. The temperature is lowest early in the morning and rises by night. The commonest cause of feeling cold is low external temperature. There can be several other causes like hypothyroidism, liver diseases, low Vit B12, adrenal insufficiency, liver failure and as a side effect of some drugs. Chills are also felt when a fever is about to start in case of malaria and bacterial infections due to release of toxins. One can also feel chilled if you are about to break into viral fever.
All these can be tested by simple blood tests. Hope this helps. Please let me know if there is any thing else and do keep me posted. Take care!
Sometimes a low body temperature can be due to abnromal thyroid function. This can be diagnosed by a blood test.