Instant heat patches Patch will gradually heat once exposed to air. Taking 30minutes to reach full temp For the tempoary relif of mild muscular aches ,Back Pain Tummy Pain , Neck Pain , Sore Joints , Period Pain, For Heat Therapy On The Go!! Patch size 13cm x 9.5cm ARTG Registered:312363 Directions for use: Only open Instant Heat Patches pack when ready to use. Open outer packet - patch begins heating when exposed to air. Remove backing stickers from patch. Apply sticky side to underclothing at area that requires treatment and press firmly. Remove gently and dispose of after use. Single use only. DO NOT APPLY HEAT PATCHES DIRECTLY TO SKIN.