Heat Rash (Prickly Heat)

Heat rash, also called prickly heat or miliaria, happens when sweat ducts become blocked and sweat gets trapped under the skin. This causes tiny red bumps or blisters, itching, and a prickling or stinging feeling. Heat rash usually appears in areas where sweat is trapped — such as the neck, chest, back, or skin folds — and is more common in hot, humid environments.

• Blocked sweat ducts due to excessive sweating in hot or humid weather
• Clothing: Tight or occlusive clothing that prevents sweat from evaporating
• Risk factors:

Infants (immature sweat ducts)

Adults who are overweight or sweat heavily

People on bed rest or those wearing bandages in hot conditions

Living or working in high-humidity climates

Most cases clear up on their own with cooling and keeping the skin dry. Medical evaluation is needed if the rash is extensive, very itchy, recurrent, or accompanied by fever, chills, or signs of skin infection (redness, swelling, pus).