1. Remove the warmer from the package and shake it 5-6 times to activate the heating process.
2. Wait for 10 minutes since the WARMER MUST BE FULLY WARM before being put in a confined space (pocket, glove, etc.).
3. Ideally, activate them in an ambient environment of 20°C (at home, in the car, etc.).
4. At 0°C or above 2,000 m altitude, blow on them several times. The warmth and moisture of your breath will accelerate the start of the reaction.