Review on 5200MAh Electric Rechargeable Double-Side Hand Warmer | Portable Pocket Hand Warmers & Phone Charger For Outdoor Sports | Heat Therapy Great For Women & Men In Winter By BRIGENIUS by Frank Bruton

I have used this a few times. Gets warm quickly and has different settings which is nice. This is a great size. I can fit it in my pocket with my hands to warm them up. I was trying a few things out exile testing it. I put it near my feet and had a throw blanket on and it got my feet toasty warm. I haven't tried this yet but seems like you could put in a pocket under a coat (like a shirt pocket) and should warm you up nicely.