Brown fat is also called brown adipose tissue (BAT). The adipose tissue (See: Adipose tissue) consists of white fat and brown fat. The function of the brown fat cells is to burn fat in the form of heat (chemical energy) when needed. These cells contain uncoupled protein, which helps the release of energy in the form of heat. Brown fat is a key constituent for humans to combat cold temperatures. Brown adipose tissue is significantly present in infants in areas around the trachea, pancreas, and kidneys. Though it is believed that most of the brown adipose tissue transforms into white fat or white adipose tissue, recent studies on positron emission tomography has shown that human adults do have significant amounts of brown fat deposits in them stored in the upper chest and the neck areas. For people with diabetes, brown fat is known to activate insulin sensitivity. This means that people suffering with diabetes and having impairment of insulin function benefit from the activation of brown fat. Brown fat activation can also increase bone density and lower levels of C-reactive protein. However, it has been stated that in non-diabetics, activation of brown fat has led to mild elevation of blood sugar levels.