Exotherm is a scientific term that refers to a process or reaction that releases heat. In the context of nail services, an exothermic reaction occurs during the curing or hardening process of nail coating products like UV gels and liquid and powder systems. When the tiny molecules in these products join together to form polymer chains, a small amount of heat is released. This is normal and usually goes unnoticed, but in certain circumstances it can cause the product to become noticeably warm or even hot, which is referred to as a heat spike.
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