Use as follows:
Open the package and remove the heater.
The contents react directly to the oxygen and it starts to get hot. Full heat is reached after between 5-10 min.
Place the heater in your shoe or on the socks, and enjoy 8 hours (can be divided) 40 ℃ heat!
After use, dispose of the heater in the usual household waste.
The foot warmers have an adhesive side so that they stay in place.