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This article is for general information only and does not replace medical advice. If in doubt, contact your paediatrician or midwife.

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Heat Rash in Babies (Miliaria)

Heat rash occurs when babies are overdressed or during hot weather. Sweat glands become blocked, forming small red bumps — usually on the neck, in skin folds, and on the upper body. Although harmless, they itch and make your baby fussy.

Possible Causes

  • 1Overheating from too many layers of clothing (most common reason!)
  • 2High humidity and heat in summer
  • 3Immature sweat glands in newborns
  • 4Synthetic clothing that doesn't wick away sweat
  • 5Fever — elevated body temperature can trigger heat rash

What You Can Do

  • Remove excess clothing — rule of thumb: one layer more than you're wearing
  • Move to a cool room or use a fan (not pointed directly at baby)
  • Light, airy cotton clothing
  • Lukewarm bath — NO soap or bath additives
  • Let affected areas air dry, no powders or creams

When to See a Doctor

  • Bumps become pustular or crusted (bacterial superinfection)
  • Baby has fever along with the rash
  • Rash spreads and worsens despite cooling
  • Baby is unusually sleepy or feeds poorly (heat stroke signs)

Age-Specific Notes

Newborns are most susceptible as their sweat glands are still immature. Particularly common in the first year. Well-meaning grandparent advice ('The child is cold!') often leads to overheating. The neck test reveals if your baby is too warm: if the back of the neck feels sweaty and hot, your baby is overheated. Cool hands and feet are NORMAL and not a sign of being cold.

Frequently Asked Questions

How do I tell heat rash apart from eczema?
Heat rash appears SUDDENLY in warm conditions and disappears quickly with cooling. Eczema is chronic, the skin is dry and flaky, and it appears in typical locations (elbow creases, behind the knees). If unsure, photograph the rash and show it to the paediatrician.
Can I put powder on heat rash?
NO. Powder (including baby powder) can further block the clogged sweat glands and worsen the problem. There's also an inhalation risk. Simply letting air reach the skin is the best treatment.

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This article is for general information only. It does not replace individual medical advice. If you have concerns, contact your paediatrician, midwife, or call emergency services.