Brown adipose tissue is present in small mammals (e.g., mice) and in newborn humans. Most of it disappears in adult humans. The cells in both types of fat are called adipocytes although they differ in origin, structure, and function in the two types of tissue.
On the left hand, index finger. It's not the index finger you wear it on. Left hand, ring finger. The finger that you would wear a wedding ring on.
Wear your wedding band on your ring finger. Your ring finger is the finger next to your pinkie on your left hand. This tradition originated in ancient Rome, where is was believed that the vein in the ring finger ran directly to the heart.