Excitation: Bend the metal plate when the materials in the hot bag is liquid. Then the hot bag can be heated and the first heat will last about 30~50 minuters.

Revivification: Soak the cold hot bag in the boiled water 2~3 times about 15 minuters or directly boil the hot bag 15 minutes. Bend the metal plate again when the crystal fully become liquid state and the second heat will last 40~80 minuters