Heat Stress in workplace

1. Dr C G Acharya
Barge Doctor
Aset Marine Services Pvt Ltd Singapore

4. Workers who are exposed to extreme heat or
work in hot environments may be at risk of heat
stress. Exposure to extreme heat can result in
occupational illnesses and injuries.
Heat stress can result in heat stroke, heat
exhaustion, heat cramps, or heat rashes.
Heat can also increase the risk of injuries in
workers as it may result in sweaty palms,
fogged-up safety glasses, and dizziness.
Burns may also occur as a result of accidental
contact with hot surfaces or steam

5. Workers at risk of heat stress include outdoor workers and
workers in hot environments such as firefighters, bakery
workers, farmers, construction workers, miners, boiler room
workers, factory workers, and others. Workers at greater risk
of heat stress include those who are 65 years of age or older,
are overweight, have heart disease or high blood pressure, or
take medications that may be affected by extreme heat.

6. Factors that May Cause Heat-
related Illness
• High temperature and humidity
• Low fluid consumption
• Direct sun exposure (with no shade) or extreme
heat
• Limited air movement (no breeze or wind)
• Physical exertion
• Use of bulky protective clothing and equipment
• Poor physical condition or ongoing health
problems
• Some medications
• Pregnancy
• Lack of previous exposure to hot workplaces
• Previous heat-related illness

7. Heat Stroke
Heat stroke is the most serious heat-related disorder. It occurs when the
body becomes unable to control its temperature: the body's
temperature rises rapidly, the sweating mechanism fails, and the body is
unable to cool down. When heat stroke occurs, the body temperature
can rise to 106 degrees Fahrenheit or higher within 10 to 15 minutes.
Heat stroke can cause death or permanent disability if emergency
treatment is not given.

8. Symptoms
Symptoms of heat stroke include:
•Hot, dry skin or profuse sweating
•Hallucinations
•Chills
•Throbbing headache
•High body temperature
•Confusion/dizziness
Slurred speech

9. First Aid
Take the following steps to treat a worker with heat stroke:
•Call 911 and notify their supervisor.
•Move the sick worker to a cool shaded area.
•Cool the worker using methods such as:
Soaking their clothes with water.
Spraying, sponging, or showering them with water.
Fanning their body.

10. Heat Exhaustion
Heat exhaustion is the body's response to an excessive loss of
the water and salt, usually through excessive sweating.
Workers most prone to heat exhaustion are those that are elderly,
have high blood pressure, and those working in a hot environment

11. Symptoms
Symptoms of heat exhaustion include:
•Heavy sweating
•Extreme weakness or fatigue
•Dizziness, confusion
•Nausea
•Clammy, moist skin
•Pale or flushed complexion
•Muscle cramps
•Slightly elevated body temperature
•Fast and shallow breathing

12. First Aid
Treat a worker suffering from heat exhaustion with the following:
•Have them rest in a cool, shaded or air-conditioned area.
•Have them drink plenty of water or other cool, nonalcoholic
beverages.
•Have them take a cool shower, bath, or sponge bath.

13. Heat Syncope
Heat syncope is a fainting (syncope) episode or dizziness that usually
occurs with prolonged standing or sudden rising from a sitting or lying
position. Factors that may contribute to heat syncope include
dehydration and lack of acclimatization.
Symptoms
Symptoms of heat syncope include:
•Light-headedness
•Dizziness
• Fainting

14. First Aid
Workers with heat syncope should:
•Sit or lie down in a cool place when they begin to feel
symptoms.
•Slowly drink water, clear juice, or a sports beverage.

15. Heat Cramps are muscle pains usually caused
by physical labor in a hot work environment.
Heat cramps are caused by the loss of body salts
and fluid during sweating. Workers with heat
cramps should replace fluid loss by drinking
water and/or carbohydrate-electrolyte
replacement liquids (e.g., sports drinks) every 15
to 20 minutes.

16. Heat Rash
is the most common problem in hot work
environments. Heat rash is caused by sweating and
looks like a red cluster of pimples or small blisters.
Heat rash usually appears on the neck, upper chest,
in the groin, under the breasts and in elbow
creases.
The best treatment for heat rash is to provide a
cooler,less humid work environment. The rash area
should be kept dry. Powder may be applied to
increase comfort. Ointments and creams should not
be used on a heat rash. Anything that makes the
skin warm or moist may make the rash worse.

17. The best way to prevent heat illness is
to make the work environment cooler. In
outdoor situations, this may be done by
scheduling activities during the cooler
times of the day.
However, very early starting times
may result in increased fatigue. Also,
humidity tends to be higher in the early
morning hours.
Provide air conditioned or shaded
areas close to the work area and allow
frequent rest breaks.

18. Indoor workplaces may be cooled by using air conditioning
or increased ventilation, assuming that cooler air is available
from the outside.
Other methods to reduce indoor temperature include:
providing reflec-surfaces, and decreasing water vapor pressure,
e.g., by sealing steam leaks and keeping floors dry.
The use of fans to increase the air speed over the worker will
improve heat exchange between the skin surface and the air,
unless the air temperature is higher than the skin temperature.
However, increasing air speeds above 300 ft. per min. may
actually have a warming effect.
Industrial hygiene personnel can assess thedegree of heat
stress caused by the work environment and make
recommendations for reducing heat
exposure.

19. 1)Train workers and supervisors about the hazards leading to
heat stress and ways to prevent them.
2)Allow workers to get used to hot environments by gradually
increasing exposure over a 5-day work period.
Begin with 50% of the normal workload and time spent in the hot
environment and then
gradually build up to 100% by the fifth day. New workers and
those returning from an absence of two weeks or more should
have a 5-day adjustment period.
3)Provide workers with plenty of cool water in convenient,
visible locations close to the work area.
Water should have a palatable (pleasant and odor free) taste and
water temperature should be 50- 60°F if possible.

20. 4)Remind workers to frequently drink small amounts of water
before they become thirsty to maintain good hydration.
Simply telling them to drink plenty of fluids is not sufficient.
During moderate activity,
in moderately hot conditions, at least one pint of water per
hour is needed. Workers should drink about 6 ounces or a
medium-sized glass-full every 15 minutes. Instruct workers
that urine should beclear or lightly colored.
5) Be aware that it is harmful to drink extreme amounts of
water. Workers should generally not drink more than a total
of 12 quarts of fluid in 24 hours.
•6)Reduce the physical demands of the job, such as excesive
lifting, climbing, or digging with heavy objects. Use
mechanical devices or assign extra workers.

21. 7)Monitor weather reports daily and reschedule jobs with high
heat exposure to cooler times of the day. When possible, routine
maintenance and repair projects should be scheduled for the
cooler seasons of the year.
•8)Schedule frequent rest periods with water breaks in shaded
or air-conditioned recovery areas.
•9)Workers are at an increased risk of heat stress from personal
protective equipment (PPE), especially from wearing semi-
permeable (penetrable) or impermeable clothing (such as Tyvek
or rubber),
when the outside temperature exceeds 70°F, or while working at
high energy levels. These types of clothing materials trap heat
close to a worker’s body. Workers should be monitored by
establishing a routine to periodically check them for signs and

22. Recommendations for Workers
•Workers should avoid exposure to extreme heat, sun exposure,
and high humidity when possible. When these exposures cannot
be avoided, workers should take the following steps to prevent
heat stress:
•Wear light-colored, loose-fitting, breathable clothing such as
cotton.
Avoid non-breathing synthetic clothing.
•Gradually build up to heavy work.
•Schedule heavy work during the coolest parts of day.
•Take more breaks in extreme heat and humidity.
Take breaks in the shade or a cool area when possible.
•Drink water frequently. Drink enough water that you never
become thirsty. Approximately 1 cup every 15-20 minutes.
•Avoid alcohol, and drinks with large amounts of caffeine or
sugar.
•Be aware that protective clothing or personal protective