Myxedema crisis (MC) is a rare but life-threatening illness characterized by multi-system organ impairmentfrom thyroid hormone deficiency that is often brought on by an eliciting event. We present the case of MCwith a rapid progression of hypothermia, altered mental status, and respiratory failure that was instigatedby a flash burn to the face. The patient’s condition was refractory to rewarming and supportive efforts untilthyroid hormone was replaced. This case illustrates the need for a high index of suspicion for patients with arapid onset of metabolic encephalopathy immediately after an injury or burn.