How warmth can take your pain away

How do heat patches work for muscle tension and pain?

Heat is used in orthopaedics as a supportive pain‑relieving measure. And for good reason: applying heat improves blood flow, helps with muscle tension, sprains, strains and loosens connective tissue. 

A continuous application of heat at 40 °C for 8 hours to the affected body area can effectively relieve nonspecific pain. Heat penetrating about 2 cm into the tissue supports the regeneration of damaged tissue and stimulates the thermal receptors. 

Because the temperature stimulus competes with the pain stimulus for transmission to the brain, this thermal stimulation reduces pain perception, so that the pain is perceived as less intense. Increased blood flow helps clear metabolic waste more quickly and lowers the concentration of pain‑producing mediators. Through improved circulation, more oxygen and nutrients reach the injured area. This helps the body repair the damaged muscle. 

What advantages do heat patches have over conventional heat applications?

During the day, you usually do not have the option of using a hot water bottle without restricting your freedom of movement. This is where a heat patch comes into play, placed on the painful area. The advantage of heat patches is that they can be worn comfortably and discreetly under clothing and do not restrict movement. 

How does the warming effect of capsaicin heat patches work?

There are two types of these pain‑relieving aids: capsaicin heat patches and catalytic heat patches containing activated charcoal and iron. Capsaicin is a pepper extract from dried, ground chilli peppers. There are also patches with the synthetic capsaicin derivative nonivamide. 

Capsaicin causes increased release of the neurotransmitter substance P and irritates the skin, causing peripheral blood vessels to dilate. This creates a warming sensation on the skin, while the patch itself does not become hot. The pain receptors at the nerve endings in the skin are stimulated, causing itching or burning sensations and thereby reducing the sensitivity of pain receptors, so pain impulses from muscle tension are less frequently transmitted to the brain. 

What are catalytic heat patches and how do they generate heat?

Catalytic heat patches contain activated charcoal and iron, which generate heat through a chemical reaction with oxygen. In this case there is no skin irritation – the heating cells inside the patch warm up on their own. 

These patches are made from a special non‑woven material so that oxygen can quickly enter the interior of the non‑woven chambers. The mixture of active ingredients in the heat patch releases its effect about 30 minutes after opening the airtight packaging. The heat of approx. 40 °C lasts for at least 8 hours. After that the patch cannot be reheated.

Heat patches in everyday life – practical, effective, soothing

• The patch with activated charcoal and iron should be used immediately after opening the packaging, as soon as it comes into contact with air. Note that this heat patch cannot be shared.
• Remove the protective film from the heat patch, position it on the affected area and press to stick it on. Ask someone to help if you need to apply the patch to your back or neck.
• Note that only one heat patch should be applied to the same skin area per day. Typically it is worn for up to 8 hours.
• After 8–12 hours of use, wait at least 12 hours before applying a new patch.
• The heat patch must not be worn over medicated patches. Avoid using lotions, creams, body oils as well as medical pain creams and ointments before applying a heat patch, otherwise skin irritation may occur. The patch should be applied to clean, dry skin.
• If you use a heat patch for menstrual pain, it should be attached to underwear, not to the skin.
• After applying a capsaicin patch, wash your hands thoroughly with water and soap. Be careful with eyes, mucous membranes and open wounds: capsaicin must not come into contact with these areas.
• Heat patches should not be worn at night. In bed there is increased heat exposure, which can intensify the patch's effect and lead to severe skin irritation or even burns.
• When using a capsaicin heat patch, skin redness is possible. Sensitive skin may experience irritation and allergic reactions. If the initial burning sensation is too uncomfortable or persists well beyond 30 minutes, the patch should be removed.
• Older people should be aware that bodily sensations may be reduced and the risk of burns increased.
• Do not apply heat patches to damaged skin, bruises or swellings. Heat patches are not suitable for children under 12 years. The same applies to people who cannot remove the patch themselves.
• A catalytic heat patch must be removed prior to magnetic resonance imaging (MRI).
• Diabetics should consult a doctor before using a heat patch, as skin sensation may be reduced. Therefore a diabetic may not notice skin irritation.
• Note that for acute sports injuries, bruises and strains, cooling rather than heating should be applied. In such cases heat patches are not suitable.

With these tips you can achieve a soothing warming sensation that can relax cramped muscles and effectively relieve pain!