Abstract: A hand warmer with double-sided heating is provided. The hand warmer includes a hand warmer body with a cambered surface on one side and a flat surface on the other side. Through the flat surface of the hand warmer body, two hand warmer bodies can be attached together. The hand warmer body includes an outer shell, a heating film disposed on each of two sides of the outer shell, and an aluminum alloy thermally-conductive cover plate covered on the heating film. The outer shell is internally provided with a Hall switch that is tightly attached to the flat surface and a magnetic steel located on a side of the Hall switch. Flat surfaces of the two hand warmer bodies are opposite and attached to each other.

Abstract: A modular hand warmer includes a heating casing and a power supply component. The heating casing is hollow and provided therein with a power supply cavity. The heating casing is provided with a first outlet communicating with the power supply cavity. The heating casing is provided with a heating element. The shape of the power supply component is adapted to the power supply cavity. The power supply component is capable of being detachably inserted into the power supply cavity from the first outlet. The power supply component is capable of being electrically connected to the heating element. The first outlet is provided at the heating casing to facilitate the installation of the power supply component into the power supply cavity from the first outlet and the removal of the power supply component from the first outlet, which is conducive to the replacement and use of the power supply component.