Heat rash, also known as prickly heat or summer rash, is an eruption of little bumps (and sometimes tiny blisters) on the skin that can show up when your baby overheats. (babycenter.com)
My daughter gets tiny blisters from scratching, and I scratch until scabs appear, mostly around my neck and shoulders. (articles.chicagotribune.com)
Dress baby in clothing made of 100 % cotton — this helps avoid prickly heat, which causes a red rash resembling tiny blisters. (homemade-baby-food-recipes.com)