If you are having difficulty getting your temp up it could be an iodine deficiency. I take Lugols solution and it really helps. If that is not enough than I would suspect a low functioning thyroid. I also have been taking a thyroid extract from Swansons, but since I started exercising I have been able to cut back. I also recommend the Exergen temporal thermometer. I never had much success with oral temps. You can now get one at Walmart. It is a great investment.