FHM TRAINING TOOLS
This training presentation is part of FHM’s
commitment to creating and keeping safe
workplaces.
Be sure to check out all the training programs
that are specific to your industry.
Heat Stress
What Is Heat Stress?
•
Working or playing where it is hot puts stress
on our body's cooling system.
• When the heat is combined with other
stresses such as hard physical work, loss of
fluids, fatigue or some medical conditions, it
may lead to heat-related illness, disability and
even death.
• This can happen to anybody--even if you are
young and fit.
Heat Stress
•
Heat stress is usually a concern in the tropics
or the South.
• This is especially true in states like Florida
and Texas, when people are frequently
exposed to the heat.
How We Cope With Heat
•
Your body is always generating heat and
passing it to the environment.
• The harder your body is working, the more
heat it has to lose.
• When the environment is hot or humid or has
a source of radiant heat (for example, a
furnace or the sun), your body must work
harder to get rid of its heat.
Heat Stress
•
If the air is moving (for example, from fans)
and it is cooler than your body, it is easier for
your body to pass heat to the environment.
• Workers over 40 should be more careful
because of a reduced ability to sweat.
Controlling Heat Stress
Acclimatization
•
The longer you do hard work in the heat the
better your body becomes at keeping cool.
• If you are not used to working in the heat then
you must take a week or two to get
acclimated or used to the heat.
• If you were ill or away from work for a week or
so you can lose your acclimatization.
• There are several ways to get acclimated:
Heat Stress
•
•
•
•
If you are experienced on the job, limit your time in
the hot environment to 50% of the shift on the first
day and 80% on the second day.
You can work a full shift the third day.
If you are not experienced on the job (for example,
a new worker) you should start off spending 20%
of the time in the hot environment on the first day
and increase your time by 20% each following day.
Instead of reducing the exposure times to the hot
job, you can become acclimated by reducing the
physical demands of the job for a week or two.
Heat Stress
•
If you have health problems or are not in
good physical condition, you may need longer
periods of acclimatization.
• Hot spells in warm states like Florida or Texas
last long enough to allow acclimatization.
• When it is hot, consider some of the following
engineering and administrative controls.
Heat Stress Hazards
Heat Rash and Sunburn
Heat
Rash
Sunburn
Cause
Symptoms
Hot humid
Red bumpy
environment; rash with
plugged
severe itching.
sweat
glands.
Treatment
Change into dry
clothes and
avoid hot
environments.
Rinse skin with
cool water.
Prevention
Wash regularly
to keep skin
clean and dry.
Too much
exposure to
the sun.
If the skin
blisters, seek
medical aid. Use
skin lotions
(avoid topical
anesthetics) and
work in the
shade.
Work in the shade:
cover skin with
clothing; wear
suntan lotions with
a sun protection
factor of at least
15. People with fair
skin should be
especially
cautious.
Red, painful,
or blistering
and peeling
skin.
Heat Cramps
Cause
Heavy sweating
drains a
person's body
of salt, which
cannot be
replaced just by
drinking water.
Symptoms
Painful cramps
in arms, legs or
stomach which
occur suddenly
at work or later
at home.
Cramps are
serious
because they
can be a
warning of other
more
dangerous
heat-induced
illnesses.
Treatment
Move to a cool
area; loosen
clothing and
drink cool salted
water (1 tsp.
salt per gallon
of water) or
commercial fluid
replacement
beverage. If the
cramps are
severe or don't
go away, seek
medical aid.
Prevention
When working
in the heat,
workers should
put salt on their
food (if on a
low-salt diet,
this should be
discussed with
a doctor). This
will give the
body all the salt
it needs; don't
take salt tablets.
Fainting
Cause
Not enough
blood flowing to
the head,
causing loss of
consciousness.
Symptoms
Sudden fainting
after at least two
hours of work;
cool moist skin;
weak pulse.
Treatment
Fainting may be
due to a heart
attack or other
illness.
GET MEDICAL
ATTENTION.
Assess need for
CPR. Move to a
cool area; loosen
clothing; make
person lie down;
and if the person
is conscious, offer
sips of cool water.
Prevention
Reduce activity
levels and/or
heat exposure.
Drink fluids
regularly.
Workers should
check on each
other to help
spot the
symptoms which
often precede
heat stroke.
Heat Exhaustion
Cause
Inadequate salt
and water intake
causes a person's
body's cooling
system to start to
break down.
Symptoms
Heavy sweating;
cool moist skin;
body temperature
very high ; weak
pulse; normal or
low blood
pressure; person is
tired, weak,
clumsy, upset or
confused; is very
thirsty; or is
panting or
breathing rapidly,
vision may be
blurred.
Treatment
GET MEDICAL
AID.
Prevention
Reduce activity
levels and/or heat
exposure. Drink
This condition can fluids regularly.
lead to heat stroke, Workers should
which can kill.
check on each
Move the person
other to help spot
to a cool shaded
the symptoms
areas; loosen or
which often
remove excess
precede heat
clothing; provide
stroke.
cool water to drink
(salted if possible);
fan and spray with
cool water.
Heat Stroke
Cause
If a person's
body has used
up all its water
and salt, it will
stop sweating.
This can cause
body the
temperature to
rise.
Symptoms
High body
temperature and
any one of the
following: the
person is weak,
confused, upset or
acting strangely;
has hot, dry, red
skin; a fast pulse; a
headache or
dizziness. In later
stages, a person
may pass out and
have convulsions.
Treatment
CALL AN
AMBULANCE.
Prevention
Reduce activity
levels and/or
heat exposure.
This condition
Drink fluids
can kill a person regularly.
quickly. Remove Workers should
excess clothing; check on each
fan and spray the other to help spot
person with cool the symptoms
water; offer sips which often
of cool water if
precede heat
the person is
stroke.
conscious.
Modifying Work and the
Environment
•
Management and the Safety Committee can
reduce heat stress in the following ways:
Engineering Controls
•
Control the heat at source through the use of
insulating and reflective barriers (insulate
furnace walls).
• Exhaust hot air and steam produced by
specific operations.
• Reduce the temperature and humidity
through air cooling.
• Provide air-conditioned rest areas.
Heat Stress
•
Increase air movement
• Reduce physical demands of work task
through mechanical assistance (hoists, lifttables, etc.).
Administrative Controls
•
Health and safety committees should assess
the demands of all jobs and have monitoring
and control strategies in place for hot days.
• Increase the frequency and length of rest breaks.
• Schedule hot jobs to cooler times of the day.
• Provide cool drinking water near workers and
remind them to drink a cup every 20 minutes or
so.
Heat Stress
•
•
•
Workers should salt their food well,
particularly while they are acclimating to
a hot job (workers with a low salt diet
should discuss this with their doctor).
Assign additional workers or slow down
work pace.
Make sure everyone is properly
acclimated.
Heat Stress
•
Train workers to recognize the signs and
symptoms of heat stress and start a 'buddy
system' since people are not likely to notice
their own symptoms.
• Pregnant workers and workers with a medical
condition should discuss working in the heat
with their doctor.
Personal Protective Equipment
•
•
•
•
•
Light clothing should be worn to allow free air
movement and sweat evaporation.
Outside, wear light-colored clothing.
In a high radiant heat situation, reflective
clothing may help.
For very hot environments, air, water or icecooled insulated clothing should be
considered.
Vapor barrier clothing, such as acid suits,
greatly increases the amount of heat stress
on the body, and extra caution is necessary.
Heat Stress
•
•
Threshold Limit Values for Heat Stress
published by the American Conference
of Governmental Industrial Hygienists
used as reference.
These values are based on preventing
fit, acclimated workers' core
temperatures from rising too high.
Examples of Permissible Heat Exposure Threshold Limit Values
Work Load
Work – Rest Regimen
(per hour)
Light
Moderate
Heavy
Temperature in Degrees F
Continuous Work
86
80
77
75%Work – 25%Rest
87
82
78
50%Work – 50%Rest
89
85
82
25%Work – 75%Rest
90
88
86