The diagnosis of hypothermia may be obvious, particularly when there is a history of severe environmental exposure (e.g. after a prolonged search and rescue effort in a wilderness setting).

However, the history may be more subtle in the elderly, housebound patient or the wet patient who has been exposed to less severe cold temperatures.

Mild or moderate hypothermia can present with non-specific symptoms, such as confusion, dizziness, chills, fatigue, hunger or dyspnoea.

The patient may exhibit poor judgment, slurred speech, irritability, lassitude or altered mental status. The patient may even demonstrate paradoxical undressing in response to prolonged cold stress, or they may make a rocking motion.

The slurred speech and ataxia may mimic a stroke, alcohol intoxication or high-altitude cerebral oedema.

Learning bite

Obtaining a full set of vital signs (temperature, pulse, blood pressure and respiratory rate) is vital in the patient with altered mental status to avoid missing subtle cases of hypothermia.