ESI No Dol Thermal Gel (Cold-Heat). It is a thermal gel pad, which can store cold or heat depending on needs. Ideal for people who work with weight, seniors or athletes. Essential in any medicine cabinet. Helps relieve - Lumbago pain, torticollis, rheumatism or hypothermia, using its heat application function. - Bruises, sprains or hyperthermia, using its function of applying cold. Indicated to relieve any type of joint pain in which it is necessary to apply heat or cold to the skin. * Reusable. * Approximate measurements: 17 x 13 cm. - To obtain heat: Immerse the bag in boiling water for a maximum of 5 minutes or heat in the microwave at 350w for 1 minute. Wrap with a clean cloth before applying to skin. - To obtain cold: Leave the bag in the freezer for at least an hour and a half. Wrap with a clean cloth before applying to skin.