Heatstroke
Cause
Occurs from a breakdown in heat regulatory mechanisms causing cessation in sweating.
Major factor is increased ambient temperature, particularly with high humidity.
When the body’s temperature regulation fails, the core temperature keeps rising.
The hyperthermia can cause multiple organ system failure.
Two types
Classic heatstroke—arises when the person has not exerted himself or herself.
Exertional heatstroke—arises when working or exercising in a hot environment.
Medical risk factors need not be present.
This type of heatstroke can occur in a healthy individual.
Risk factors
Elderly
Infants and children
Medical conditions
Congestive heart failure
Arteriosclerosis
Diabetes mellitus
Hyperthyroidism
Substances—alcohol, caffeine, cocaine, heroin, and Phencyclidine (PCP)
Dermatologic/rheumatologic conditions that make it difficult to lose sweat
Congenital absence of sweat glands
Ectodermal dysplasia
Severe scleroderma
Medications
Drugs that decrease heat loss
Anticholinergics, phenothiazines, and antihistamines decrease sweating.
Diuretics, calcium-channel blockers, and β-blockers all decrease cardiovascular reserve.
Barbiturates depress the central nervous system (CNS) response to heat production.
Drugs that may increase heat production—amphetamines, neuroleptics
Drugs that depress thirst—butyrophenones
Heatstroke from lithium in combination with the selective serotonin reuptake inhibitor (SSRI) fluoxetine has been reported
Signs and symptoms
Prodromal symptoms
Generally absent
Some patients may complain of headache, vertigo, lightheadedness, abdominal distress, or confusion
Skin—dry, hot
Vital signs
