Description

• A core temperature of <35°C (95°F)
• May take several hours to days to develop
• Patients with cold-water immersion can appear to be dead but can still be resuscitated (1)[C].
• System(s) affected: All body systems
• Synonym(s): Accidental hypothermia

Epidemiology

• Predominant age: Very young and the elderly
• Predominant sex: Male > Female

Geriatric Considerations
More common due to lower metabolic rate, impaired ability to maintain normal body temperature, and impaired ability to detect temperature changes.

Prevalence
Estimates vary widely due to lack of pathologic evidence, and it is usually considered a secondary cause in diagnosing disorders.

Risk Factors

• Alcohol consumption
• Bronchopneumonia
• Cardiovascular disease
• Cold-water immersion
• Dermal dysfunction (burns, erythrodermas)
• Drug intoxication
• Endocrinopathies (myxedema, severe hypoglycemia)
• Excessive fluid loss
• Hepatic failure
• Hypothalamic and CNS dysfunction
• Malnutrition
• Mental illness; Alzheimer disease
• Prolonged cardiac arrest
• Prolonged environmental exposure
• Renal failure
• Sepsis
• Trauma (especially head)
• Uremia

General Prevention

• Appropriate clothing, with particular attention to head, feet, and hands
• For outdoor activities, carry survival bags with space blankets for use if stranded or injured.
• Avoid alcohol.
• Alertness to early symptoms and initiating preventive steps (e.g., drinking warm fluids)
• Identify medications that may predispose to hypothermia (e.g., neuroleptics, sedatives, hypnotics, tranquilizers).

Etiology

• Overwhelming environmental cold stress
• Decreased heat production
• Increased heat loss
• Impaired thermoregulation

Commonly Associated Conditions

• Addison disease
• CNS dysfunction
• Congestive heart failure
• Diabetes
• Hypopituitarism
• Hypothyroidism
• Ketoacidosis
• Pulmonary infection
• Sepsis
• Uremia