Caltech Heat Illness

Prevention ProgramCaltech Environment, Health, and Safety Office

Learning Objectives

☼ Describe the Heat Illness Prevention Plan

☼ List the Risk Factors of Heat Illness

☼ Identify Types of Heat Illnesses

☼ Learn How to Prevent Heat Illness

☼ Identify Basic Responsibilities

What is Heat Illness?

☼ Our body has an internal thermostat• controls our temperature by sweating

for cooling

☼ Heat illness happens when• our bodies overheat and do not

have enough water to cool us

Our Prevention Plan

☼ Recognize the Risk Factors☼ Know Heat Illness Signs and

Symptoms☼ Emergency Procedures☼ Identify Methods to Prevent

Heat Illness

Risk Factors

☼ Environment• Air temperature and humidity• Radiant heat from the sun• Air movement• Workload severity and duration• Protective clothing and equipment worn by

employees

☼ Ourselves• Age, health, and degree of acclimatization• Water, caffeine, and alcohol consumption• Prescription medication use that may affect

the body’s water retention

Importance of Sweat

☼ Sweat is triggered when• our body reaches an internal

temperature at which sweat glands are triggered to create sweat on the skin for cooling

☼ Skin is the body’s Radiator • moving air over the skin increases

heat exchange for cooling

Heat Illnesses

☼ Sweat loss • reduces blood plasma volume (the liquid part of

blood)• may cause an electrolyte (e.g. sodium,

potassium, chloride) imbalance in the blood– stresses the cardiovascular system and contributes to

a faster increase in body temperature that may lead to either:

– Heat Exhaustionor

– Heat Stroke

Heat Exhaustion

☼ Symptoms• Weakness,

giddiness, nausea, headache

• Clammy, moist skin – pale or flushed

• Temperature normal or slightly above

☼ Treatment• Immediately move

victim to cool area, provide water and rest

• Anyone who loses consciousness or vomits requires further medical help

Heat Stroke

☼ Symptoms• Confusion,

delirium, convulsions, or unconsciousness

• Hot, dry skin and rapid pulse

• Very high temperature – above 103° F

☼ Treatment• Medical

emergency!• Immediately cool to

reduce core temperature

– Loosen/remove extra clothing

– Pour or sponge water over person or immerse

– Fan vigorously

Emergency and First Aid

☼ Report:• your or other co-worker’s signs and

symptoms of heat illness to you supervisor.

☼ Supervisors are to:• contact Security (x5000) to obtain medical

help.• be prepared to give an accurate work

location.

Steps for Preventing Heat Illness

☼ Acclimate☼ Dress for conditions☼ Drink plenty of fluids before

you’re thirsty☼ Access to shade

Acclimate – get used to the HEAT

☼ About 7 to 10 days☼ Work for short periods in the heat

• gradually increasing in time and intensity

☼ Stay in good shape• conditioned muscles work more

efficiently and generate less body heat

☼ If you spend time out of the heat due to vacation • you may need to acclimate again

Dress for Heat Conditions

☼ Lightweight, loose-fitting clothing• promotes heat loss by exposing sweat-laden

skin to the air• allows sweat to evaporate

☼ Heavy clothing and equipment • traps heat and sweat against the skin• forces the body to produce more sweat to

cool itself

Yes No

Drinking Water

☼ Don’t wait for warning signs☼ Drink water up to a quart each hour☼ Include sodium-containing snacks or

food to replace the electrolytes in body fluid

It is a Caltech safety policy to provide enough water for employees to drink one quart per hour or

have a means to replenish during the shift.

Caffeinated Drinks

☼ Caffeine is a drug, not a nutrient☼ Caffeine is a diuretic

• increases urine production• adds to dehydration

Preventing Heat Illness with Shade

☼ Do heaviest work in cooler (shaded) areas or in cooler time of day

☼ A variety of cooling methods include:• Ventilation, fans• Vehicle air conditioning, if applicable• Shielding or tent shading when air conditioning is not

available

It is Caltech’s safety policy to have access to shade, especially for those needing a break.

Supervisor Responsibilities

☼ Ensure employees receive heat illness training before working outdoors.

☼ Provide adequate water supplies • 2 gallons per person per

shift, • shade and/or air-

conditioned vehicles, if applicable.

☼ Be alert to any employee symptoms or signs of heat illness and take precautions as needed.

☼ Prepare, maintain, and follow emergency response plans in the event of an employee heat illness.

Employee Responsibilities

☼ Attend heat illness training☼ Follow heat illness

precautions when working outdoors• including frequently drinking

water

☼ Immediately report • any symptoms or signs of heat

illness in yourself or co-workers

Review Questions

☼ What are the Risk Factors to Heat Illness?• Environmental factors such as temperature and

humidity and personal factors such as health and water use

☼ How can you recognize Heat Stroke?• Confusion, delirium, convulsions, hot, dry skin

☼ How much water do you need to prevent heat illness?• At least one quart per hour per employee or two

gallons per shift per employee