I had the bright idea to use this to both warm my hands and power a heat pad for extra heat, but that did not work as expected. It just cannot supply the needed power for both.
Pressing the power button toggles between heating and powering, which is fine if you are only using this for temporary warmth and need to top up your phone battery in between. But if you need to do both at the same time, this is an expensive hand warmer that does not eliminate the need for an extra power bank.
It is also a bit bulky and heavy, but that is to be expected from a high-capacity battery. If you don't need 12 hours of heat or some combination of heating and charging your phone, you are better off with something cheaper and lighter.
