Safety: heat stress
Safety on residential construction sites has changed
dramatically over the last couple of decades. Safety is to be thought of before
anything else to protect the workers, the equipment they are using and the
buildings that they are working on.
Since the warm weather has finally arrived supervisors and
workers alike need to be aware of the dangers of working in area’s or
environments where the heat is high. They need to aware of what is called “heat
stress” on their workers.
Construction sites are very different then normal offices or places of business in that when the weather is nicer and the sun is shining longer they work longer hours to take advantage of this, this is good for the wallet but can be bad for your health if you are not careful. Heat stress is a real concern on today's construction sites.
Construction sites are very different then normal offices or places of business in that when the weather is nicer and the sun is shining longer they work longer hours to take advantage of this, this is good for the wallet but can be bad for your health if you are not careful. Heat stress is a real concern on today's construction sites.
What is Heat Stress?
Working or
playing where it is hot puts stress on your body’s cooling system. When heat is
combined with other stresses such as hard physical work, loss of fluids,
fatigue or some pre-existing medical conditions, it may lead to heat-related
illness, disability and even death.
How do we cope with heat?
Your body is always generating heat and passing it into the environment.
The harder your body works, the more heat it has to lose. When the environment
is hot and/or humid or has a source of radiant heat (such as a furnace or the
sun), your body must work harder to get rid of heat.
If the air is moving (for example, by fans) and it is cooler than your
body, it is easier for your body to pass heat into the environment.
Workers on medication or with pre-existing medical conditions may be
more susceptible to heat stress because some medication and/or medical
conditions may impair the body’s response to heat. Such workers should speak to
their personal physicians to see if their medication(s) and/or health
condition(s) affect their ability to work in hot environments.
Heat-Stress–related disorders
A summary of heat-stress-related disorders, causes, symptoms, treatment
and prevention is presented in the table below.
Cause
|
Symptoms
|
Treatment
|
Prevention
|
|
Heat
rash
|
Hot
humid environment; plugged sweat glands.
|
Red
bumpy rash with severe itching.
|
Change
into dry clothes and avoid hot environments. Rinse skin with cool water.
|
Wash
regularly to keep skin clean and dry.
|
Heat
cramps
|
Heavy
sweating from strenuous physical activity drains a person’s body of fluid and
salt, which cannot be replaced just by drinking water. Heat cramps occur from
salt imbalance resulting from failure to replace salt lost from heavy
sweating.
|
Painful
cramps occur commonly in the most worked muscles (arms, legs or stomach);
this can happen suddenly at work or later at home.
Heat cramps are serious because they can be a warning of other more dangerous heat-induced illnesses. |
Move to
a cool area; loosen clothing, gently massage and stretch affected muscles and
drink cool salted water (1½ to 2½ mL salt in 1 litre of water) or balanced
commercial fluid electrolyte replacement beverage. If the cramps are severe
or don’t go away after salt and fluid replacement, seek medical aid. Salt
tablets are not recommended.
|
Reduce
activity levels and⁄or heat exposure. Drink fluids regularly. Workers should
check on each other to help spot the symptoms that often precede heat stroke.
|
Fainting
|
Fluid
loss, inadequate water intake and standing still, resulting in decreased
blood flow to brain. Usually occurs in unacclimatized persons.
|
Sudden
fainting after at least two hours of work; cool moist skin; weak pulse.
|
GET
MEDICAL ATTENTION. Assess need for cardiopulmonary resuscitation (CPR). Move
to a cool area; loosen clothing; have the person lie down; and if the person
is conscious, offer sips of cool water. Fainting may also be due to other
illnesses.
|
Reduce
activity levels and⁄or heat exposure. Drink fluids regularly. Move around and
avoid standing in one place for too long. Workers should check on each other
to help spot the symptoms that often precede heat stroke.
|
Heat
exhaustion
|
Fluid
loss and inadequate salt and water intake causes a person's body's cooling
system to start to break down.
|
Heavy
sweating; cool moist skin; body temperature over 38°C; weak pulse; normal or
low blood pressure; person is tired and weak, and has nausea and vomiting; is
very thirsty; or is panting or breathing rapidly; vision may be blurred.
|
GET
MEDICAL ATTENTION. This condition can lead to heat stroke, which can cause
death quickly. Move the person to a cool shaded area; loosen or remove excess
clothing; provide cool water to drink; fan and spray with cool water. Do not
leave affected person alone.
|
Reduce
activity levels and⁄or heat exposure. Drink fluids regularly. Workers should
check on each other to help spot the symptoms that often precede heat stroke.
|
Heat
stroke
|
There
are two types of heat stroke:
Heat
stroke may develop suddenly or may follow from heat exhaustion.
|
High
body temperature (over 40°C) and any one of the following: the person is
weak, confused, upset or acting strangely; has hot, dry, red skin (classic
heat stroke) or profusely sweating (exertional heat stroke); a fast pulse;
headache or dizziness. In later stages, a person may pass out and have
convulsions.
|
CALL
AMBULANCE. This condition can kill a person quickly. Remove excess clothing;
fan and spray the person with cool water; offer sips of cool water if the person
is conscious.
|
Reduce
activity levels and/or heat exposure. Drink fluids regularly. Workers should
check on each other to help spot the symptoms that often precede heat stroke.
|
Controlling Heat Stress
Acclimatization
The longer you work in a hot environment, the better your body acclimatizes
to the heat. If you are ill or away from work for a week or so you can lose
your acclimatization.To become acclimatized, consider the following progressive approaches:
- If you are experienced on the job,
you should limit your shift time in hot working conditions to 50 per cent
on the first day, 60 per cent on the second day, and 80 per cent on the
third day. You should be able to work a full shift on the fourth day.
- If you are not experienced on the job
(for example, if you are a new employee), you should start off spending 20
per cent of shift time in hot working conditions on the first day and
increase your time by 20 per cent on each subsequent day. You should be
able to work a full shift in hot working conditions the fifth day.
- Instead of progressively increasing
the exposure times on the job in a hot environment, you can become
acclimatized by gradually increasing the physical demands of the job over
a week or two.
Controlling Heat Stress
Acclimatization
The longer you work in a hot
environment, the better your body acclimatizes to the heat. If you are ill or
away from work for a week or so you can lose your acclimatization.To become acclimatized, consider the following progressive approaches:
- If you are experienced on the job,
you should limit your shift time in hot working conditions to 50 per cent
on the first day, 60 per cent on the second day, and 80 per cent on the
third day. You should be able to work a full shift on the fourth day.
- If you are not experienced on the job
(for example, if you are a new employee), you should start off spending 20
per cent of shift time in hot working conditions on the first day and
increase your time by 20 per cent on each subsequent day. You should be
able to work a full shift in hot working conditions the fifth day.
- Instead of progressively increasing
the exposure times on the job in a hot environment, you can become
acclimatized by gradually increasing the physical demands of the job over
a week or two.
When there is a potential for exposure to heat stress, control measures must be taken to prevent heat exposure in the workplace. These include engineering controls, administrative controls and protective clothing. Selection of appropriate workplace controls will vary, depending on the type of workplace and other factors. Some measures may include:
Engineering controls
- Reduce physical demands of work task
through mechanical assistance (hoists, lift–tables, etc.)
- Control the heat at its source
through the use of insulating and reflective barriers (e.g.
insulate furnace walls)
- Exhaust hot air and steam produced by
operations
- Reduce the temperature and humidity
through air cooling
- Provide cool, shaded work areas
- Provide air–conditioned rest areas
- Increase air movement if temperature
is below 35°C (e.g.
use fans).
Administrative and work practice
controls
- The employer should:
- Assess the demands of all jobs and
have monitoring and control strategies in place for hot days and hot
workplaces
- Increase the frequency and length of
rest breaks
- Schedule strenuous jobs to cooler
times of the day
- Provide cool drinking water near
workers and remind them to drink a cup about every 20 minutes, or more
frequently, to stay hydrated
- Caution workers to avoid direct
sunlight
- Assign additional workers or slow
down the pace of work
- Make sure everyone is properly
acclimatized
- Train workers to recognize factors
which may increase the risk of developing a heat related illness and the
signs and symptoms of heat stress and start a “buddy system” since people
are not likely to notice their own symptoms
- Investigate any heat–related
incidents
- Trained First Aid providers should be
available and an emergency response plan should be in place in the event
of a heat related illness.
- Pregnant workers and workers with a
medical condition – or those taking certain medications – should discuss
with their physicians about working in the heat
Protective clothing
- Light summer clothing should be worn
to allow free air movement and sweat evaporation
- If working outdoors, wear
light-coloured clothing, preferably long-sleeve shirt and pants, and cover
the head to prevent exposure to direct sunlight
- In a high radiant heat situation,
wearing reflective clothing to shield radiant heat may help
- For very hot environments, consider
air, water or ice–cooled insulated clothing
- Vapour-barrier clothing, such as
chemical protective clothing, greatly increases the amount of heat stress
on the body. Extra caution such as heat strain (physiological) monitoring
is necessary, if vapour-barrier clothing is worn
Construction
companies should have programs in place so that all employee’s understand the
risks and know what to do in these situations.
Rob Abbott
Village Builders
Information
gathered for this post was taken from the ministry of labour webstie. To see
more about this here is the link to it.