Herbal Brews - Body warmers Heat Pouch - Self Heating Warmer - Body Warmer Pouch, Long Lasting Natural Safe and Odorless Single Use Air Activated Heat Packs for Body, Up to 10 Hours of Heat - 5 Pcs

I can't thank enough when I was under -4 degrees. Once has to perfectly use it(sticky side sticked on dress).

Did not work. Took loong time to heat up and the heat was also minimal

Works after 30- 45 min , exposed to air

This heats up fast and gets very nice and warm. The best part is that the patch comes with a sticky side so you can attach it to the inside of your jacket or pants. The other products in this category are just pouches and they keep falling. Additionally, these patches are much flatter than others, so they don't look bulky.

It says 8 hour but I found only an hour warmness not so much heat as well.. Will not recommend

Such a bad and fraud product...not at all effective..waste of money

The price is at high end, but the quality is very good. It kept me warm for the whole day. Especially when I am walking or sitting outdoor with below zero degree during my last snow trek, this is especially helpful.

While I try to compare with other brand products, this one is not that effective