Heat Stress Lecture Review

Comprehensive flashcards covering the physiology of heat stress, causal factors, types of heat disorders, and engineering/administrative controls.

What is the normal internal temperature the human body attempts to maintain during both rest and activity?

$$98.6^{\circ}F$$

How much water can the human body lose per hour during heavy work in heat?

$1-2$ liters

What happens to blood volume after 3-6 hours of sweating without intervention, and how does this affect heat regulation?

Blood volume drops to low levels, meaning there is less blood to carry excess heat to the skin or oxygen and nutrients to muscles.

List five individual factors that affect a person's sensitivity to heat stress.

Age, weight, degree of physical fitness, degree of acclimatization, metabolism, use of alcohol or drugs, and medical conditions like hypertension.

How is Heat Stroke medically defined in terms of body temperature and symptoms?

A body temperature higher than $40^{\circ}C$ ($104^{\circ}F$) associated with neurologic dysfunction.

Define Exertional Heat Stroke (EHS).

A form of heat stroke that generally occurs in young individuals who engage in strenuous physical activity for a prolonged period in a hot environment.

Who is most commonly affected by classic nonexertional heat stroke (NEHS)?

Sedentary elderly individuals, persons who are chronically ill, and very young persons.

What are the primary signs and symptoms of a Heat Stroke?

Confusion; irrational behavior; loss of consciousness; convulsions; lack of sweating (usually); hot, dry skin; and an internal temperature that can reach $105.8^{\circ}F$.

What immediate treatment steps should be taken for a worker suffering from heat stroke?

Obtain professional medical treatment immediately, place the worker in a shady area, remove outer clothing, wet the skin, increase air movement for evaporative cooling, and replace fluids as soon as possible.

What are the common signs and symptoms of Heat Exhaustion?

Headache, nausea, vertigo, weakness, thirst, and giddiness.

What physical mechanism causes Heat Cramps?

An electrolyte imbalance caused by sweating, often attributed to both too much and too little salt.

How frequently should a worker take water in a hot environment, even if they aren't thirsty?

Every $15$ to $20$ minutes.

What is the physiological cause of Heat Collapse (fainting)?

The brain does not receive enough oxygen because blood pools in the extremities.

What is 'Prickly Heat' and why does it occur?

A heat rash manifested as red papules in areas where clothing is restrictive, occurring in skin that is persistently wetted by unevaporated sweat.

What factor predisposes an individual to heat fatigue, and what are its symptoms?

Lack of acclimatization; symptoms include impaired performance of skilled sensorimotor, mental, or vigilance jobs.

Identify the five major types of engineering controls used to manage heat stress.

1. Ventilation, 2. Air cooling, 3. Fans, 4. Shielding, 5. Insulation.

What is the difference between general ventilation and air cooling in engineering controls?

General ventilation dilutes hot air with cooler outside air, while air cooling (like air conditioning) reduces air temperature by removing heat and humidity from the air.

According to the transcript, how can radiant heat be reduced?

By using shields.