Heat rash occurs in babies when the pores of the sweat glands become blocked. This happens most often when the weather is hot or humid. As your infant sweats, little red bumps, and possibly tiny blisters, form because the blocked glands cannot clear the sweat.
To avoid heat rash, keep your baby cool and dry during warm weather.
Some helpful suggestions:
- During the hot season, dress your baby in lightweight, soft, cotton clothing. Cotton is very absorbent and keeps moisture away from the baby's skin.
- If air conditioning is not available, a fan may help cool your infant. Place the fan far enough away so that there is only a gentle breeze drifting over the infant.
- Avoid the use of powders, creams, and ointments. Baby powders do not improve or prevent heat rash. Creams and ointments tend to keep the skin warmer and block the pores.
Heat rashes and babies; Prickly heat rash; Red miliaria
Moon M, Guerrero AM, Li X, Koch E, Gehris RP. Dermatology. In: Zitelli BJ, McIntire SC, Nowalk AJ, Garrison J, eds. Zitelli and Davis' Atlas of Pediatric Physical Diagnosis. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 8.
Howard RM, Frieden IJ. Vesiculopustular and erosive disorders in newborns and infants. In: Bolognia JL, Schaffer JV, Cerroni L, eds. Dermatology. 4th ed. Philadelphia, PA: Elsevier; 2018:chap 34.
Martin KL, Ken KM. Disorders of the sweat glands. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 681.
Review Date 12/10/2021
Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.