Portable hand warmer storage box and hand warmer assembly

A portable hand warmer assembly, comprising:

• two electronic hand warmers, wherein each of the electronic hand warmers is provided with a heating element and comprises an upper surface for heating and a lower surface opposite to the upper surface;
• wherein the electronic hand warmers are capable of being detachably connected to each other in a manner that each of the electronic hand warmers is capable of warming individually through the upper surface, or the two electronic hand warmers are stacked by stacking the lower surfaces together to form a combined unit for warming;
• and a storage box, comprising a case body with at least one receiving chamber for receiving the two electronic hand warmers, wherein the case body comprises an opening corresponding to the at least one receiving chamber, allowing the two electronic hand warmers to be inserted into the at least one receiving chamber through the opening individually or in the combined unit.