<qa>  What is the area where brown fat is located in humans?The pathophysiology of pain related to fibromyalgia is not understood. This condition is difficult to diagnose and to treat. One clue may be that tender points areas which hurt typical of fibromyalgia are most densely located near the clavicles. This is also the area where brown fat is located in humans. Brown fat is typically used to maintain body temperature. Stress such as cool temperature or special diets, i.e., high fat, low carbohydrate appears to worsen the pain seen in fibromyalgia. We hypothesize that a mechanism for pain in this disease relates to activating brown fat through neural mechanisms. The nerves to brown fat also go into adjacent muscle and skin. So, when brown fat is turned on or increases in amount, collateral nerves may cause pain at the tender points. 