Heat Rash: Symptoms

What are the symptoms of heat rash?

Symptoms of heat rash include the appearance of raised bumps on your skin in the affected area that may range in color from clear to red. The type and color of rash depend on the location in the skin where sweat glands are clogged, and symptoms have a range of severity. The mildest form is called miliaria crystalline (clear, raised rash), a blockage of the sweat glands at the top layer of the skin. Types that occur deeper in the skin include miliaria rubra (reddened rash) and miliaria profunda (larger and firmer bumps that are skin colored).

Common symptoms of miliaria cystallina heat rash

Common symptoms of heat rash originating in the outermost layer of the skin include:

• Clear spots that break easily

• Spots that do not produce itching or pain

Common symptoms of miliaria rubra heat rash

Common symptoms of heat rash originating in clogged pores in the epidermis include:

• Red, raised spots

• Spots that produce itching

Common symptoms of miliaria profunda heat rash

Common symptoms of heat rash originating in clogged pores in the dermis, or deep layer of the skin, include:

• Hard, flesh-colored spots

• Heat exhaustion (rapid heart rate, confusion, nausea)

• Inability to perspire

Serious symptoms that might indicate a life-threatening condition

Heat rash may be a symptom of heat stroke, a life-threatening condition that can lead to organ failure if untreated. Seek immediate medical care (call 911) if you, or someone you are with, have any of the following symptoms:

• Change in mental status or sudden behavior change, such as confusion, delirium, lethargy, hallucinations and delusions

• Extreme thirst and dehydration

• Flushed appearance

• Rapid breathing (tachypnea) or shortness of breath

• Rapid heart rate (tachycardia)

• Very high fever (higher than 101 degrees Fahrenheit)

• Weakness (loss of strength)