0071643192.pdf

ENVIRONMENTAL EMERGENCIES

PREVENTION OFHEATILLNESS

■ Keep hydrated (drink solutions which help replete electrolytes)

■ Wear loose, light-colored clothing.

■ Stay indoors with air conditioning on hot and humid days.

Minor Heat Illness

■ Heat rash:“Prickly heat” due to blocked sweat pores

■ Heat cramps:These are painful contractions of large muscles that occur

AFTER exertion 2°to relative hyponatremia. Individuals replace evapora-

tive losses by drinking hypotonic fluids such as free water without replacing

salt. Measured electrolytes are normal. It is usually self-limited; treatment is

supportive.

■ Heat edema:Secondary to peripheral vasodilation and orthostatic pooling

of blood

■ Heat tetany:Carpopedal spasm due to hyperventilation and ↓PCO 2

■ Heat syncope:Syncope during heat stress 2°to peripheral vasodilation in

the setting of dehydration

Heat Exhaustion

This is the most common form of heat-related illness. It is characterized by

volume and/or salt depletion under conditions of heat stress. Mental status is

normal.

SYMPTOMS/EXAM

■ Dizziness, weakness, irritability

■ Headache

■ Perspiration

TABLE 13.6. Risk Factors for Heat Illness

INCREASEDHEAT

PRODUCTION DECREASEDHEATLOSS IMPAIREDMOBILITY

Thyroid storm Infants Infants and young children

Seizures Advanced age Physical or mental impairment

Severe agitation Volume depletion Acute CNS process

Exercise Impaired cardiac function Alcoholism

Acute toxicologic Skin conditions Tranquilizer or sedative use

process (eg, scleroderma, prickly heat)

Neuroleptic malignant

syndrome

Malignant hyperthermia

Medications

Anticholinergics

Psychiatric medications

β-Blockers

Diuretics