Why do my 20-month-old's cheeks get bright red and hot?
Some babies are more prone than others to develop what you describe. Red cheeks seem to be related to differences in vascular reactivity, the opening and closing of small blood vessels in the skin. When these vessels open up, or "dilate," blood flow is increased and the skin may appear red and feel warm to the touch. This dilation may be caused by fever, illness, weather changes, medications, or, in most cases, normal variation. Some skin disorders, such as eczema and keratosis pilaris, may be associated with red cheeks, but these conditions do not go away within hours as you describe. Although "rosy cheeks" may occur now and then, the changes will likely become less prominent as your son gets older.