>>2657812I prefer thermopad (
https://www.thermopad.eu), which puts over twice the active ingredient of the decathlon branded packs, but have also tried decathlon.
Warmer packs have issues activating when cold. Even in temperatures far above the cutoff for lithium battery powered warmers.
If you need enough mobility to be forced into fingered gloves, the packs can't be stuffed far enough to heat your fingers directly.
I have mild Raynaud's syndrome - it may work better for you.