Erythema ab igne following heating/cooling blanket use in the intensive care unit.

Erythema ab igne caused by chronic heat exposure presents as a net-like hyperpigmentation of the skin. We report this condition rapidly evolving due to the inadvertent use or dysfunction of an adjustable-temperature blanket in the intensive care unit. The use of heating/cooling blankets, especially in a patient with altered mental status, can result in iatrogenic erythema ab igne.