Prickly Heat is a condition where areas of the skin itch intensely, and often feel Prickly or it may sting due to overHeating.  Also known as sweat retention syndrome or miliaria rubra, Prickly Heat is a common disorder of the sweat glands.

The skin contains two types of glands: one produces oil and the other produces sweat. Sweat glands are coil-shaped and extend deep into the skin. They are capable of plugging up at several different depths, producing four distinct skin rashes.

	Miliaria crystallina is the most superficial of the occlusions. At this level, only the thin upper layer of skin is affected. Little blisters of sweat that cannot escape to the surface form. A bad sunburn as it just starts to blister can look exactly like this.
	Deeper plugging causes miliaria rubra as the sweat seeps into the living layers of skin, where it irritates and itches.
	Miliaria pustulosais (a complication of miliaria rubra) occurs when the sweat is infected with pyogenic bacteria and turns to puss.
	Deeper still is miliaria profunda. The skin is dry, and goose bumps may or may not appear.

There are two requirements for each of these phases of sweat retention: hot enough weather to induce sweating, and failure of the sweat to reach the surface.

The causes of Prickly Heat.
Evidence suggests that bacteria form the plugs in the sweat glands. These bacteria are probably normal inhabitants of the skin, and why they suddenly interfere with sweat flow is still not known.

Infants are more likely to get miliaria rubra than adults. All the sweat retention rashes are also more likely to occur in hot, humid weather.

Besides itching, these conditions prevent sweat from cooling the body, which it is supposed to do by evaporating from the skin surface. Sweating is the most important cooling mechanism available in hot environments. If it does not work effectively, the body can rapidly become too hot, with severe and even lethal consequences. Before entering this phase of heat stroke, there will be a period of heat exhaustion symptoms (dizziness, thirst, weakness) when the body is still effectively maintaining its temperature. Then the temperature rises, often rapidly, to 104-5°F (40°C) and beyond. This is an emergency of the first order, necessitating immediate and rapid cooling. The best method is immersion in ice water.

Prevention of Prickly Heat. Avoid excessive Heat and humidity and keep as cool as possible.
	Wear loose cotton clothing to encourage the evaporation of sweat and prevent further skin irritation.
	Keep baths and showers cools.
	Leave a babes nappy off for as long as possible.
	Keep rooms cool, air conditioning will help.

Symptoms
The symptoms are many small red bumps and a constant prickling or itching sensation.  The most severe forms, salt crystals may form sweat glands ducts, producing small blisters.  Itching may encourage scratching, which could lead to a skin infection.

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