Hypothermia is any core body temperature less than 35 °C. The pathophysiology involves peripheral vasoconstriction. Signs and systemic manifestations of hypothermia vary based on severity and range from shivering and altered mental status to cardiac arrest. Trauma patients are more susceptible to hypothermia, and it can be detrimental to them. Hypothermia, a component in the lethal triad, can progress to increased mortality and organ failure. The lethal triad of hypothermia, acidosis, and coagulopathy all interact with one another in a vicious cycle worsening coagulopathy; Damage Control Resuscitation aims to interrupt the lethal triad. Treatment of hypothermia depends on core body temperature, clinical condition, available resources, and the experience of the trauma team and includes passive external rewarming, active external rewarming, and active internal rewarming. The trauma team must be able to both recognize and treat hypothermia to decrease the associated morbidity and mortality and increase the patient’s likelihood of survival.