Heat-Related Illness in the
Outdoor Environment
WSU EH&S Statewide
10/07
Heat-Related Illness
Why is it important to know about heat illness?
Heat illness can effect anyone
Heat illness is dangerous
Heat illness can kill
Heat illness is preventable
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Presentation Outline
 What is a heat-related illness
 Types of heat-related illness
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 Signs & symptoms
 Contributing risk-factors
 Prevention
 Emergency response procedures
Heat-Related Illness
 Heat stress is the buildup in the body of heat generated by
the muscles during work, plus heat coming from warm and
hot environments.
 When the body becomes overheated, less blood goes to the
active muscles, the brain and other internal organs. Workers
get weaker, become tired sooner, may be less
alert,
and less
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able to use good judgment.
 As the stress from heat becomes more severe, there can be
a rapid rise in body temperature and heart rate.
 Heat exhaustion and heat stroke result when the body is
subjected to more heat than it can cope with, causing
decreased mental performance, organ damage, convulsions,
and death.
 During hot weather, heat-illness can be the underlying cause
of other injuries, such as heart attacks on-the-job, falls, and
equipment accidents arising from poor judgment.
Types of Heat-Related Illnesses
Heat Rash
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Heat Cramps
Heat Fatigue
Heat Exhaustion
Heat Stroke
Heat Rash
What to look for:
Red blister-like eruptions
Itching or prickling
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What to do:
 Get out of the sun to somewhere cool
 Keep skin dry
 Monitor for infection
 Consult physician
Heat Cramps
 A heat cramp is an involuntarily
and forcibly contracted muscle or
fibers of a muscle that don’t relax
(i.e., a muscle spasm that doesn’t relax).
 Heat cramps usually occur in the
arm, leg or stomach muscles, and
are very painful.
 Heat cramps can last a few
seconds, 15 minutes, or more,
and can occur multiple times, and
without warning.
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Heat Cramps are Painful!
 Pain from heat cramps distract a
worker, and may create serious
consequences.
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 A person’s automatic reaction is to
bend over in pain, fall down in pain, or
reach for area in pain without thought
of the result of moving quickly.
 This can be dangerous, if a person is operating
machinery, driving, on a roof, etc. when a heat
cramp occurs; a serious accident may result.
Treatment of Heat Cramps
 Get out of the heat to a cool place.
 Rest!
 Drink electrolyte-containing fluids.
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 Gently stretch the cramped muscle and
hold the stretch for ~ 20 seconds, then
gently massage the muscle. Repeat if
necessary.
 Don’t return to work in the heat this day.
Heat Fatigue
Heat Fatigue signals a person is in trouble, and
potentially headed towards heat exhaustion.
 What to look for:
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 Impaired mental or sensorimotor performance
 Fainting
What to do:
 ASAP: Stop work, get out of the heat, drink
fluids, and seek medical aid before heat
fatigue progresses to heat exhaustion.
Heat Exhaustion
 Heat exhaustion is a more serious and
advanced stage of heat-related illness
than heat fatigue.
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Beware!
 Untreated heat exhaustion can quickly
progress to heat stroke.
Danger!
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Heat Fatigue
& Dehydration
Heat
Exhaustion
Heat
Stroke
Heat Stroke Can Be Fatal!
Heat Stroke
IS
A MEDICAL
EMERGENCY
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 The body becomes so stressed that it can no
longer regulate its on own temperature & it overheats.
 Potentially, when the body can’t cool itself, body
temp can reach 106° in 10-15 minutes.
 The body literally cooks itself.
Prevent Heat-Related Illness
To prevent injury, learn to recognize
the signs and symptoms of heat
exhaustion and heat stroke.EH&S Statewide 10/07
Signs & Symptoms
Heat Exhaustion & Heat Stroke
Both heat exhaustion and stroke may exhibit:
 Red Face
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Mood changes, irritability, agitation, or confusion
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Nausea/Vomiting
Unsteady gait
Fainting
Erratic behavior
Rapid pulse
Fatigue and weakness
Dizzy or light-headed
Knowing the Difference
Can Save a Life!
HEAT EXHAUSTION
 Extreme sweating or
pale, clammy skin
 Normal to slightly
elevated temperature
HEAT STROKE
 Hot, dry skin/face that is
flushed, but not sweating
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 High temperature
(>104° F)
Only in Heat Stroke
 Chills/Shivering
 Convulsions and/or seizures
 Loss of consciousness
 Coma
 May resemble a heart attack
Heat Exhaustion
and
Heat Stroke
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Stop work, get out of the heat, drink
electrolyte-containing fluids, and seek
medical aid
How The Body Stays Cool!
The body’s thermostat is the
Hypothalamus gland, which is located in
the brain, and controls body heat.
The hypothalamus signals blood to flow
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surface of the skin to cool itself.
The body sweats.
Sweat evaporates off skin and has a
cooling effect on the blood and thus the
body.
Many things can interfere with the body’s cooling
processes or contribute to body heat production.
Contributing Factors to
Heat-Related Illness
Heat + Humidity + Other (Internal & External) Factors =
Total Heat Burden on the Body
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Humidity and Heat
Inhibit Body Cooling
 Humidity (moisture in the air) interferesEH&S
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sweat evaporating from the skin thus
interferes with the cooling of the body.
 The more humid it is, the less sweat can
evaporate, and the less body cooling occurs,
and the more chance of heat-related illness
 The hotter the temperature, the harder the
body has to work to produce enough sweat to
stay cool.
 Heat and humidity together greatly increase
the potential for heat-related illness.
Monitor
Heat and Humidity
To help keep the body’s cooling mechanisms
working properly, it is important to monitor heat
and humidity values throughout each workday
in hot and/or humid weather, and EH&S
adjust
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accordingly.
Heat Index Used to Monitor
Heat + Humidity
 Heat + humidity values = Heat Index
 The higher the temperature and humidity the
higher the Heat Index.
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 The Heat Index gives an “Apparent” EH&S
Temperature.
 The Apparent Temperature is a higher value than
temperature alone as it factors in humidity.
Monitor the Heat Index online and/or by using a Heat
Index Chart (see next slide).
Heat Index Chart
Heat + Humidity = Heat Index
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Implement
controls at
90° or
before
May feel
effects at
80°
Source: National Oceanic and Atmospheric Administration
Heat Index Warnings
Heat + Humidity = Heat Index
Heat Index
Extreme Danger
130 or higher
Implement
controls at
90° or
before
May feel
effects at
80°
General Effect of Heat + Humidity with
Prolonged Exposure & Physical Activity
Heat stroke highly likely
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Danger
105-129
Heat stroke, heat cramps, and heat
exhaustion likely, and heat stroke
possible
Extreme Caution
90-104
Heat stroke, heat cramps, and heat
exhaustion possible
Caution
80-89
Fatigue possible
Other Risk Factors
Heat + Humidity + Other Factors = Total Heat Burden
Learn to recognize risk factors and
how to mitigate them to avoid
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related illness.
Risk Factors: Direct Sun
The more direct sun, the hotter the environment.
Shield yourself or stay out of the direct sun as
much as possible.
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Sunlight is at its peak between 10AM-2PM daily; a
good time to stay out of the sun.
Risk Factors: Radiant Heat
Radiant heat is the transfer of heat energy
through the air from sun and other sources such
as, asphalt, engines, and dark surfaces.
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Radiant heat can add 15° to Heat Index
Risk Factors:
Conductive Heat
Conductive heat transfers heat to worker by
direct contact with heat sources such as
tools, equipment, and machinery.
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Risk Factors:
Limited Air Movement
 Limited air movement, such when there is
little or no wind, creates a hotter environment
as the less the air moves, the less cooling of
the body can occur.
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 For example, there is limited air movement
while working in a trench, a partially enclosed
area, vehicle cab, or on the leeward side of a
structure.
Risk Factors: Physical Exertion
The harder and longer you work, the
hotter you become.
Physical exertion increasesEH&S
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of dehydration.
Risk Factors:
Protective Clothing
Wearing PPE such as non-breathable
spray suits, gloves, boots, rain gear or
respirators can hold heat to the body
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and inhibit cooling.
Risk Factors: Personal
Age: the young and over-50 are more susceptible
to heat-related illness
Poor fitness: use more
physical exertion and
energy to do a job
Over-weight: the body
holds heat more easily and
is stressed by extra weight
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Risk Factors:
Certain Medications
Some medications can make a person more sensitive
to the effects of heat and many contribute to body
dehydration; examples are:
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Allergy medicines (antihistamines)
Cough/cold medicines
Blood pressure/heart medicines
Irritable bladder/bowel medicines
Laxatives
Mental health medicines
Seizure medicines
Thyroid pills
Water pills (diuretics)
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Consult health care provider or pharmacist for information
Risk Factors:
Medical Conditions or Illnesses
Heart conditions, diabetes,
high blood pressure, etc.
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Illness or fever
 Hangover
Risk Factors:
DIET MATTERS!
Before working in the heat:
 No heavy foods
 Harder to digest & increases
metabolic heat
 No alcohol or sugary drinks
 Dehydrate the body
 No caffeinated drinks
 Diuretic
 No carbonated drinks
• Gas bubbles limit fluid intake
 No nicotine
 Constricts blood vessels
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Risk Factors: Attitude
Ditch that “Macho” Attitude!
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Slow down, pace yourself, and take
breaks, especially on hot days!
Risk Factors: Attitude
Type-A’s: Slow the Pace to Keep from Over-Heating!
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Slow down, pace yourself, and take
breaks on hot days!
Risk Factors: Attitude
Don’t Be a Super-Hero!
These actions lead to dehydration and heat stress:
“I’m tough ~ I don’t need a water break”
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“I’m not thirsty ~ I don’t need to drink”
“I’ll lose pay, if I take a water break”
“I’ll be letting my team down, if I take a break”
“I’m new here ~ I need to prove myself”
Heat Illness Regulations
An average of 500 people die each year in
the United States by effects from heat
(EPA)
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In 2007, the State of Washington put in place
regulations to address heat related illness:
WAC 296-62-095
Heat Illness Regulations
WAC 296-62-095
Requires:
 Employers with one or more employees performing
work in an outdoor environment to implement
workplace practices designed to reduce
or
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eliminate risk of heat-related illness.
 Practices must be in writing, and must include:
 Accessibility to drinking water in sufficient quantity to provide at
least one quart per employee per hour
 Procedures to remove employees experiencing signs and
symptoms of heat-related illness from duty, to provide sufficient
means to reduce body temperature, and to determine if medical
attention is needed
 Employee training must be provided initially and
annually.
Preventing Heat-Related Illness
Supervisors prevent heat-related illness by:
Monitoring the work-day weather & heat
index
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Scheduling tasks to minimize physical
exertion
Advising employees to pace themselves
Encouraging frequent breaks on hot days
Providing radio, pager, or cell phone to
keep in contact with base and each other
Rotating job tasks
Preventing Heat-Related Illness
Supervisors prevent heat-related illness :
 By providing annual heat-related
illness awareness training
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 By providing CPR and First Aid
training
 By providing easy access to water via
water bottles, coolers, hydration
packs, and transportation to base
water supply
Preventing Heat-Related Illness
Supervisors prevent heat-related illness by:
 Providing appropriate PPE
 Cooling vests & bandanas
 Hats
 UVA/UVB rated sun glasses
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 Providing sun screen (SPF 15 or greater &
UVA/UVB effective)
Work Smart
Learn how to
Keep Cool!
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Preventing Heat-Related Illness
Work Smart
Clothing traps body heat and inhibits perspiration
Especially:
Personal protective equipment (PPE)EH&S Statewide 10/07
Heavy clothing
Multiple clothing layers
Dark-colored clothing absorbs heat
Stay Cool!
Remove PPE & excess clothing during breaks
Preventing Heat-Related Illness
Work Smart
Wear appropriate clothing:
 Light-colored
 Light-weight
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 Natural fibers
 Hat with a brim
 Cooling vest or bandanas
may be helpful in some
cases
Apply appropriate sunscreen to exposed skin
Preventing Heat-Related Illness
Work Smart: Acclimatize
Acclimatization is Extremely Important!
 People can collapse, become easily fatigued, make
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mistakes, get into accidents, or develop
related illnesses, if not properly acclimatized
 Many of us travel across the state, nation, or over
seas for our work
 Take special care, if you are used to a cooler
climate and are going to a hot/humid climate
Go Prepared!
Preventing Heat-Related Illness
Work Smart: Acclimatize
 Plan in extra time (several days) to
adjust to hot working conditions
 Gradually build up exposure time, and
adjust work routines, to increase heat
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tolerance
Preventing Heat-Related Illness
Work Smart: Acclimatize
Supervisors and co-workers pay special
attention to employees that are:
 New
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 Just returning from work from being sick
 Are absent for more than 2 weeks
 Just moved from a cooler climate
 During heat-wave events
Preventing Heat-Related Illness
Work Smart: Physical Exertion
Produces Internal Heat in the Body
Consider:
What kind of work will be performed?
How hard is the work?
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How long is the work task/period?
Photo credit: http://www.sullys.com.au/LawnMowing.htm
Preventing Heat-Related Illness
Work Smart
 Alternate heavy work with light work
 Schedule the hardest work for cooler parts of the
day
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 Pace yourself
 Work in the shade or out
of direct sun
Increase frequency of breaks when:
 Conditions are very hot
 Work requires high exertion levels
 Protective clothing limits evaporative cooling
Preventing Heat-Related Illness
Work Smart: Stay Hydrated
Proper hydration is key to preventing heat illness
 When dehydrated the amount of sweat that can
be produced decreases, and the body can’t cool
itself
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 Drink water throughout the day to replace body
fluid lost by sweating
 Do not wait for thirst before drinking water
 It is also important to incorporate electrolytecontaining drinks in your daily fluid intake
 Drink 8-16 ounces of water before work to
pre-hydrate
Preventing Heat-Related Illness
Work Smart: Stay Hydrated
 Drink 1 quart or more of water over the course of
an hour when the work environment is hot, and a
person sweats more than usual
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 This is to replace the 2 quarts of sweat per hour the
body can produce in hot environments
~1 cup every 15 minutes
Persons who are on restricted fluids, or with
medical conditions that heat or bright light effect
consult a physician before working in the heat
Preventing Heat-Related Illness
Work Smart: Stay Hydrated
Drinking water sources:
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Be closeable & have a tap
Clearly marked
Suitably cool
Individual cups provided
Bottled water
Hydration packs called camelbacks
-users sip water through a tube
Hydration pack
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Photo credit: UC Davis
Worker wearing hydration pack
Preventing Heat-Related Illness
Work Smart
ESTABLISH A BUDDY SYSTEM!
Keep an
on co-workers for symptoms
of heat illness such as crankinessEH&S
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Having Trouble in the Heat?
All Activity
If you become:
Light-headed
Weak
Have a pounding heart
Confused
Faint
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Trouble breathing
Notify Supervisor
Take a Break and Rest
In a cool place
Drink fluids
Loosen or shed unnecessary clothing
Lie down
If a Co-Worker Is Having
Trouble in the Heat
 Transport the person to base, or to a cooler, shaded area so the
person can rest and lay down.
 Get help on the way: call 911, or have base call 911, and then
alert the supervisor.
 Do not leave person alone!
 Loosen and remove heavy clothing that restricts evaporation
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and cooling.
 If person is alert and not nauseated, provide fluids such as cool
water, juice, sports drinks, or non-caffeinated soft drinks.
 Fan the person, spray or mist
with cool water, apply wet cloth
to skin.
 Do not further expose the
person to heat any more that
day.
Get Help on the Way!
Call 911!
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Call when a person does not
feel better in about 15 minutes.
Call sooner if they show any
signs of heat stroke!
SECONDS COUNT!
If You Suspect Heat Stroke
WHILE WAITING FOR MEDICAL HELP TO ARRIVE
Cool the person using whatever methods available
 Apply ice packs under arms & to the groin area
 Place the person in a cool shower
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 Spray them with cool water from a hose
 Sponge the person with cool water
 If the humidity is low, wrap person in a cool wet sheet and fan
them vigorously
 Immerse the person in a tub of cool water
Do not try to give unconscious
persons fluids to drink.
If You Suspect Heat Stroke
If emergency 911 medical personnel are
delayed, call the hospital emergency
room for further instruction EH&S Statewide 10/07
In Summary: Work Smart!
 Know the signs and symptoms of heat
related illnesses and take them seriously
 Stay hydrated - Drink water/fluids
frequently
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 Consider sports drinks when sweating a lot
 Monitor Heat Index
Avoid alcohol, caffeinated
drinks, and heavy meals
before or during work
Photo credit: www.csao.org
In Summary: Work Smart!
Plan work tasks for heat relief
Pace yourself
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Acclimatize
Wear appropriate clothing
Keep an eye on your buddy
Take breaks
Stay Cool!
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