The primary culprit behind this epidermal prison is heat and humidity. In tropical climates or during summer heatwaves, the body produces sweat faster than the ducts can discharge it. Infants are particularly vulnerable because their sweat ducts are not fully developed, which explains why prickly heat is a near-universal experience of babyhood. Adults are not immune; athletes, individuals confined to bed rest with fevers, and those wearing occlusive clothing or heavy creams are prime candidates. Furthermore, certain medications, such as bethanechol or clonidine, can increase sweat production or ductal obstruction, turning a routine medication into a dermatological nuisance.

Most cases are not serious and resolve on their own once the skin is cooled. Prickly Heat | Cedars-Sinai

: Often called "prickly heat," this occurs deeper in the epidermis. It causes red, inflamed bumps and an intense prickly or itchy sensation.