Products
Heat pads and wraps with iron powder are available in pharmacies and drugstores, among others (e.g. ThermaCare, Dolor-X Hot Pad, Hansaplast, HerbaChaud with herbs).
Structure and properties
The pads contain elemental iron powder, salt, activated carbon, vermiculite and water. After opening the package, oxygen from the air reaches the iron powder, which begins to oxidize. This exothermic reaction releases heat to the environment. This is oxygen corrosion, in which the iron rusts to iron hydroxide/oxide. The salt, activated carbon and water are needed for the reaction to occur efficiently (like rusting a car). Vermiculite serves as an insulator.
Effects
The overlays have warming, muscle-relaxing, circulation-enhancing and thus pain-relieving properties. They locally release heat to the skin, underlying tissues and muscles. The duration of action depends on the product and ranges from about 8 to 12 hours. The maximum heat of about 40°C (ThermaCare) is reached after about half an hour.
Areas of application
For the treatment of muscle and joint pain, for example, neck tension, shoulder pain, back pain, after overexertion, strains and arthritis.
Dosage
According to the instructions for use. The pads are taken out of the package and applied or glued on just before use. They are used for the specified duration of action. Persons 55 years of age and older should apply the compresses over thin clothing (T-shirt, underwear) and not directly to the skin. They can also be applied this way if they feel too hot. The compresses can only be used for one treatment and cannot be “recharged”. Do not put them in the microwave!
Contraindications
- Use during sleep or directly on the skin in the elderly.
- Fresh sports injuries, bruises, swelling.
- Combination with other types of heat or with liniments.
- Application on diseased, injured or damaged skin.
- Application on body parts without heat sensation
- Application to persons who can not remove the overlay themselves (eg children).
- Application of a damaged product
- Wearing tight clothing
The full precautions can be found in the leaflet.
Interactions
Heat pads should not be combined with other types of heat or with liniments. The overlays must be removed before an MRI examination.
Adverse effects
Possible adverse effects include skin irritation and local burns. The occurrence of skin redness is normal. A disadvantage is that the overlays can only be used once. This is in contrast to other heat overlays such as cherry pit pillows, hot water bottles or cold hot packs.
