All Temp hot/cold packs are great for both treatments! Take the swelling and pain away with the cold pack and increase the blood flow with hot pack. For a hot pack, they can be heated in the microwave or by placing in hot water. Great to increase blood flow and help relieve pain. For cold pack treatment just place them in the refrigerator, or the freezer. They will stay soft and pliable even when frozen! Cold packs really reduce swelling and relieve aches and pains. Even when warm sounds good, cold usually helps more. You can even alternate them; use cold first then heat the pack and use the warm.