Prickly heat

Prickly heat occurs when your sweat glands become blocked.

If you sweat excessively, it is easier for dead skin cells and bacteria on your skin to collect in your sweat glands. If these glands become blocked, the sweat is trapped underneath your skin in tiny swollen pockets. It also seeps into the nearby tissue and irritates your skin.

When the pockets burst and release sweat, this causes a stinging, prickling sensation that gives the condition its name.

Causes of prickly heat

Prickly heat is usually caused by being in a hot climate, which makes you sweat more than usual.

Other causes are:

• spending long periods of time in bed (due to an illness or a long-term health condition, for example), because immobility and illness can make you sweat, especially if you have an electric blanket and other warm bedding,
• dressing in too much clothing in winter, and
• sitting too close to a fire or heater.