Heat patcheshttps://www.kangzhimei.net/heat-patch-oem/ provide portable warming through a controlled exothermic reaction. Understanding the mechanisms behind heat patch technology allows for proper and effective use.
When exposed to oxygen in the air, ingredients in heat patches such as iron powder, activated charcoal, salt, and water initiate an oxidation reaction. This reaction generates heat safely up to 104°F. The rate of reaction is controlled to slowly release heat over 6-12 hours or longer, depending on formulation.

Insulating outer layers made of materials like non-woven fabrics or polyethylene help retain the heat and allow gradual dissipation over time. Adhesive layers also conduct the warmth directly to the skin for localized comfort. As the ingredients deplete over the usage period, the patches naturally cool down.
Since heat patches are directly applied to the skin, the body’s natural regulation mechanisms prevent over-heating or burns. Peak temperatures are reached shortly after application, then gradually decrease. Proper instructions advise on maximum wear times and re-application frequencies to maintain safe, consistent warming.
The warming effect increases blood circulation to affected areas and helps provide pain relief. Users often apply heat patches to joints or muscles to ease arthritis, back pain, cramps and strains. The boost in blood flow accelerates healing by carrying more oxygen and nutrients to afflicted areas.