Heat Rash, Sunburn, or Sun Poisoning: How Are They Different?

Jun 02, 2022


Skin Health

Heat Rash, Sunburn, or Sun Poisoning: How Are They Different?

While summer activities like water play, backyard barbeques, and outdoor sports are enjoyable and fun-filled, they’re accompanied by the risk of sunburn. After hours in the sun, it is common to experience red patches on your face and hands. However, these may indicate other skin conditions such as heat rash and sun poisoning with symptoms including redness, itchiness, and painful blisters.

While mild symptoms can be treated at home, sun poisoning may require medical intervention. Knowing the difference between sunburn, sun poisoning, and heat rash is essential for proper treatment.

Heat Rash, Sunburn, and Sun Poisoning: What Are They?

Heat Rash

Heat rash occurs when sweat gets trapped in the skin due to clogged sweat ducts, causing irritation. It is common in skin folds and places where clothing rubs against the skin, including the shoulders, neck, and chest.


After minutes to hours of excessive exposure to the UV rays from the sun or artificial sources like sunlamps, sunburn causes red, tender, or itchy skin that feels hot to the touch.

Sun Poisoning

This refers to a severe sunburn caused by prolonged exposure to the sun that damages the underlying immune system. Flu-like symptoms, blistering, and dehydration can occur.

Heat Rash, Sunburn, and Sun Poisoning: How Are They Caused?

Heat Rash

  • Sweat glands that are yet to be developed (in newborns)
  • Wearing tight synthetic fabrics
  • Prolonged bed rest
  • Wearing a non-porous bandage


  • Pale complexions
  • Working outdoors
  • Lack of sun protecting clothing or sunblock
  • Certain medications that can increase your sensitivity to the sun

Sun Poisoning

  • Chemical peels made from alpha-hydroxy acids
  • Antibiotics and oral contraceptives
  • Extended time at the beach
  • Applying citrus oil before going out in the sun
  • Residing in mountain regions

Heat Rash, Sunburn, and Sun Poisoning: What Are the Complications?

Heat Rash

The most common complication of heat rash is secondary infection from heat exhaustion and scratching, causing itchy and inflamed pustules. People with darker complexion are more likely to develop dark or light spots due to inflammatory skin conditions (also known as post-inflammatory hyperpigmentation or hypopigmentation). However, such spots will go away within a few weeks.


Prolonged exposure to the sun can cause:

  • Premature aging (fine lines, freckles, and discoloration)
  • Skin cancer
  • Eye damage (red, dry, gritty, and painful eyes, cataracts, macular degeneration, and pterygium)

Sun Poisoning

If left untreated, sun poisoning can cause:

  • Dehydration
  • Infection that may spread to your bloodstream
  • Premature wrinkles

If you are experiencing symptoms similar to heat rash, sunburn, or sun poisoning, visit one of our urgent care clinic in Irvine, urgent care clinic in Fountain Valley, or urgent care clinic in Costa Mesa, CA, right away. We are here for you when you need us and will provide appropriate diagnosis and treatment to help restore your health quickly.



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