Cold is often a thyroid issue. If you get a a thyroid test, from what I have heard, a saliva test is best and have TSH, free T3 and free T 4 done. However, even the best test for thyroid doesn't always work. You can test normal and still have the symptoms. Also, they have revised the limits as of 2001 yet most labs and most drs. haven't changed to the new standards, leaving many hypothyroids out in the "cold" Are you super tired at times, constipated, foggy in the brain, do you have dry skin, do you have tendinitis, any eye problems (dry, gritty eyes or double vision), slow pulse, low resting early morning body temp - below 98.0F, slow reflexes, etc, etc. You could have even just one of these symptoms and be hypothryoid. I feel that many people in the US are hypo and that is contributing to the obesity problem due to the fact that in many communities they are putting fluoride into the water and fluoride slows the thyroid, and also, the drs are not following the new standards, so many hypothyroid people are not properly diagnosed and just cannot seem to lose weight. I am not properly diagnosed right now, and am gaining weight despite a very limited diet.