The present case report describes the occurrence of myxedema coma, a rare but severe manifestation of hypothyroidism with a high mortality rate. The diagnostics of unclear unconsciousness are often difficult in the preclinical setting. A thorough assessment of the medical history is of great importance when a metabolic or endocrinological cause is assumed. During the emergency treatment of comatose patients stabilization of the vital functions, e.g. airway, breathing and circulation, is of high priority. The key for a beneficial outcome in patients with myxedema coma is the early treatment with hormones