ThermaCare® patented heat cell technology combines iron, oxygen, water, and salt in single-use HeatWraps. The heat cells produce real heat to stimulate healing right where you need it. ThermaCare® HeatWraps work by allowing real heat to penetrate damaged tissue, which increases blood flow and accelerates the body’s natural healing process.

The heat cells contain a mixture of ingredients that react with air to provide low-level heat. ThermaCare® patented heat cell technology combines iron, oxygen, water, and salt in single-use HeatWraps. The chemical reaction is called iron oxidation, which occurs naturally in the environment.

ThermaCare® HeatWraps are made from cloth-like materials called “nonwovens” and are the same materials used in disposable products like diapers and feminine hygiene pads.

Each heat disc is designed to heat to about 104°F (40°C) for 8 hours. That’s just above your body's normal core temperature of 98.6°F.

  • Iron reacts with oxygen in the air to provide heat. That process is called iron oxidation.
  • Sodium chloride (salt) makes the rate of reaction between iron and oxygen faster.
  • Sodium thiosulfate controls hydrogen generation.
  • Water also is necessary for the iron oxidation reaction.
  • Charcoal allows the iron powder to have a surface to react to inside the heat discs. The surface of this charcoal has been treated (activated) to have special properties.
  • Sodium polyacrylate controls the level of water present in the heat cells.

ThermaCare® relieves pain by going to work right at the site of pain. It relaxes the muscle and increases blood flow in the area. On the other hand, oral pain medications have to be ingested and provide relief by working through the bloodstream and stopping the production of prostaglandins.

No, the printing will not come off on your skin. Note that the printing on ThermaCare® HeatWraps is on the clothing side of the wrap, so it shouldn’t come into contact with your skin when used as directed.

No, the printing will not come off on your clothes.

ThermaCare® has warmed up when it feels warm to the touch. Extensive testing has shown that ThermaCare® heats to about 104°F (40°C) within 30 minutes and maintains this temperature for 8 hours.

Don’t wash or moisten a ThermaCare® HeatWrap because it will deactivate the heat cells. While excessive moisture or wetness will affect the ability of the heat cells to heat efficiently, average body perspiration will not affect the HeatWrap performance.

Safe Usage & Disposal

  • No, ThermaCare® HeatWraps are designed for single use and provide long-lasting, powerful pain relief and relaxation of tight muscles by delivering real heat.
  • ThermaCare® works by using iron particles that start reacting when exposed to air. This reaction gives off heat. Once the iron is used up, it can’t be reactivated or recharged. So after the product stops heating, it won’t reheat and should be disposed of properly. ThermaCare® should not be used in microwave ovens, as the HeatWrap may catch on fire.

No, definitely not. Cutting the HeatWrap may damage the heat cells. Damaged heat cells can lead to increased risk of burning. Don’t use a HeatWrap that has damaged or cut heat cells.

No. If the HeatWrap is damaged or ruptured, contain the contents and dispose of it properly. If you’ve ingested any of the contents, rinse your mouth with water and call a Poison Control Center immediately. If heat cell contents come in contact with your skin or eyes, remove wrap, rinse affected area with water, and seek professional assistance immediately.

You can safely wear more than one ThermaCare® HeatWrap as long as they’re in different locations. Don’t wear more than one HeatWrap in the same place at the same time. Be careful not to overlap heat cells or wear any HeatWraps under tight-fitting clothing, belts or waistbands. Check your skin frequently during use, and if you find irritation, stop use immediately.

For best results, wear ThermaCare® for the full 8 hours. Using ThermaCare® for more than the recommended time can increase the risk of skin irritation or burns. ThermaCare® shouldn’t be used more than 7 days in a row. ThermaCare® Menstrual HeatWrap shouldn’t be used more than 4 days in a row. If during or after this time the pain you’re treating remains unchanged or worsens, consult your doctor, as this may be a sign of a more serious condition.

No. The fastening adhesive on the ThermaCare® Menstrual HeatWrap wasn’t designed to be attached to the skin. ThermaCare® Menstrual should be attached to clothing so the dark sides of the heat cell are against your skin. Do not apply the adhesive to your skin; it may cause irritation. If applied incorrectly, the device may not work properly.