Reusable. Use in first aid treatment of bumps bruises, sprains, factures, minor burns, snake bites, insect bites, minor bleeding, nosebleeds, headaches, toothaches, fever, backaches, sunstroke, dislocations, fatigue, itching, cramping, etc. Squeeze, shake, apply. Instantly cold. Reaches therapeutic controlled temp every time. Safe, non-toxic, no frostbite. Insulated on one side, energy is retained for longer periods of time and is focused on the application site, not on the hand holding the pack.