noun
small brazier; hand-warmer
A small, portable charcoal brazier used to warm the hands, traditionally used in winter.
祖母は冬になると手あぶりを使っていた。
My grandmother used a hand-warmer in winter.
火鉢 is a larger charcoal brazier for heating a room, while 手あぶり is a small, portable one specifically for warming the hands.
Compound of 手 (hand) and あぶり (warming, roasting), from the verb あぶる (to warm over a fire).