of the most overlooked hazards that can be encountered in the workplace is heat.
Heat stress is often considered a seasonal problem, associated with
employees working outside in the hot summer sun.
However, it can be found throughout the workplace at any time of year.
The need for employees and supervisors to be aware and prepared for hot
and sticky situations becomes a workplace priority.
Heat stress is a serious problem that can affect all varieties of
employees on the job.
It is not only dangerous to the employee's health, but to fellow
employees as well because the victim may be unable to perform job duties in a
WHAT IS HEAT
stress is defined as a condition in which the total net heat load on your body
from internal heat production and external sources exceeds your body's capacity
to cool itself.
Heat strain is the term used to describe the physiological response to
heat stress. There
are several factors that may reduce one’s tolerance to heat stress, such as
chronic illnesses, obesity, alcohol use, drug use, and temporary illnesses such
as the flu. Although
tolerance to heat stress will vary from person to person, heat strain will
generally decrease an employee’s judgment and workmanship.
When an employee is subjected to sustained levels of heat stress, the
real problems begin.
The potential for accidents and the likelihood of the employee sustaining
heat-related illnesses increase.
SOURCES OF HEAT
The higher the surrounding air temperature, the more heat stress occurs.
When the surrounding air temperature is below your body temperature,
increased airflow can be a great way to avoid heat stress.
However, when the surrounding air temperature is above your body
temperature, increased airflow transfers more heat to your body!
Humidity determines the rate at which sweat evaporates from your skin and
cools your body.
High levels of humidity can severely reduce your body's capacity to cool
The sun, hot asphalt, steam pipes, radiators, and ovens produce radiant heat.
The greater the source of radiant heat, the greater the potential of
It is produced by your body in relation to the work that you are doing. The more
strenuous the work, the more heat your body produces and the harder it must work
to eliminate it.
you move, your body heats up.
Perspiring is one way your body cools off.
Your body also directs more of your blood to your skin, which is why you
may look flushed when you're hot.
When your body overheats, it begins to try to cool off.
While your body is trying to cool itself off, other jobs your body must
do may not get done.
symptoms start out mild, but grow serious if left unmonitored and untreated.
Early symptoms include reduced mental and physical performance.
Heat rash can result from sweaty skin.
Painful muscle spasms and heat cramps often result from excessive loss of
fluids and electrolytes (if they are not replaced).
severe cases of heat strain can result in heat-induced fainting or loss of
Dehydration and circulatory strain from diverted blood flow can lead to
Dizziness, headaches, nausea, general confusion, and a loss of strength
are serious signs of heat exhaustion and should be given immediate
these warning signs can lead to heat stroke.
When heat stroke occurs, the body loses its capacity to cool itself and
completely shuts down.
You may lose consciousness and may suffer convulsions. Your body
temperature is far above normal, there is no sweat, and your skin becomes very
hot and dry. Permanent
damage or death may result if left untreated.
a victim gets heat cramps, pains, or spasms, they are most often in the
arms, legs, or abdomen.
(You can also get heat cramps from drinking too many cold liquids or by
drinking them too quickly).
The victim will also be perspiring heavily.
Massage or use firm pressure on the muscle that is cramping.
Small sips of water will help cool the victim's body.
Move the victim into the shade or a cooler (not cold) place.
suffering from heat exhaustion will have some or all of the following
symptoms: sweaty, clammy, flushed, or pale skin, dizziness, weakness, nausea,
rapid and shallow breathing, headache, vomiting, or fainting.
Lay them down in a cooler (not cold) place, with feet raised and tight
Give them sips of cool water.
Call emergency medical personnel, especially if there is vomiting or
means the body has gone into crisis.
Call emergency medical personnel immediately.
If the person has stopped breathing, administer CPR.
Move the victim to a cooler area and, if possible, soak the person in a
cool bath. Use
a fan or cold packs if available.
Keep the victim lying down with feet raised.
than respond to a medical emergency, your first objective should be to locate
and evaluate all jobs that may result in excess heat stress to employees. The
second objective is to minimize the risks of heat disorders or illnesses among
employees exposed to hot conditions.
takes about 4-7 days to get used to unusual heat.
Over this time, your body learns to adapt, sweating more, conserving body
salt, and reducing cardiovascular stress.
Work schedules should take this acclimatization into consideration.
one of the best ways to prevent heat stress in the workplace is through
education. It is important for all employees to understand the dangers of heat
stress, how to recognize the early symptoms, how to treat problems, how to
recognize heat illnesses in their fellow employees, and how to prevent problems
from occurring in the first place. Once employees have a good understanding of
heat stress, their judgements about their own conditions play an important role
in providing for their safety.
should monitor both the workplace environment and the individual employee for
susceptibility to heat stress.
There are some instances when monitoring the individual rather than the
environment may be more appropriate to ensure employee safety.
(For example, an employee wearing protective clothing may suffer heat
stress in a relatively cool environment.)
combat your body's loss of water and body salt during heat stress, you need to
frequently replace the lost fluids by drinking water or electrolyte-enriched
may not be thirsty, but your body can still be losing as much as three gallons
of water a day in hot weather.)
in fluids on a regular basis by schedule rather than by waiting for thirst.
Often by the time you are thirsty you are already beginning to experience
some of the early symptoms.
Beverages such as soft drinks, coffee (caffeine), tea, or alcohol
contribute to dehydration and should not be used to replace lost fluids.
working outside or in high heat atmospheres, the proper clothing is also
loose-fitting, light clothing that allows airflow should be worn in hot humid
conditions. Some situations in which protective clothing (such as body suits)
must be worn can increase your heat load.
Special precautions and training may be required in these instances.
frequent breaks in a cool place.
Adopt a work/rest schedule or schedule high exposure tasks during the
coolest times of the day (or even delay them until cooler weather).
controls can be simple and inexpensive, and may even enhance productivity by
Increase air movement that aids in sweat evaporation for cooling purposes.
This can be very effective provided the air temperature is below body
Although not always practical, it will greatly reduce heat stress by cooling the
air and reducing the humidity.
Provide relief by blocking the source from the employee.
They can range from hats or tents that provide shade from outdoor sun, to
heat reflecting curtains that provide a barrier from ovens and steam pipes.
Reducing the workload and metabolic rate of the employee will also reduce their
potential for heat-related illnesses.
Using power-assisted tools and machinery or changing the work methods
will accomplish this also.
Some jobs require that employees perform under extreme conditions where exposure
to very high heat loads can't be avoided.
Personal protective equipment may be the best or only solution for safety
in those situations.
Some examples of protective equipment are heat reflective clothing, ice
vests which conduct heat from the skin, circulating air systems that enhance
evaporation and convective cooling when using cool dry air, and liquid cooling
systems which remove body heat through conduction.
structure of your heat stress program should focus on employee safety.
An effective program includes some or all of the following:
Job safety analysis, supervisor and employee education and training, acclimatization, provisions for frequent fluid replenishment, medical screening, work/rest regimens, personal and/or area monitoring, engineering controls where feasible, protective equipment when needed, and complete documentation of the program along with any related employee records.