Whether you work in a hot smelting plant or outdoors in the summer months, heat exposure can be dangerous. Workers who are exposed to extreme heat or work in hot environments may be at increased risk of heat stress.
In foundries, steel mills, bakeries, smelters, glass factories, and furnaces, extremely hot or molten material is the main source of heat. For people working outdoors in jobs such as construction, road repair, open-pit mining and agriculture, summer sunshine provides the hot environment. In laundries, restaurant kitchens, and canneries, high humidity adds to the heat burden. In all cases, the cause of heat stress is a working environment which can potentially overwhelm your body's ability to deal with heat.
"Heat stress" is a buildup of body heat generated from a combination of the effort you exert while working, the environment (air temperature, humidity, air movement, radiation from the sun, or hot surfaces/sources), and the clothing and equipment you wear.
Most people feel comfortable when the air temperature is between 20°C and 27°C and the when relative humidity ranges from 35 to 60%. When air temperature or humidity is higher, you may feel uncomfortable but your body can cope with a little extra heat. However, very hot environments can increase your internal body temperature several degrees above the normal temperature of 37°C, overwhelming your body's natural cooling systems and leading to a variety of serious and possibly fatal conditions.
Illnesses caused by heat exposure
The risk of heat-related illness is different for each person. You are at greater risk of heat stress if you have pre-existing health issues (e.g. are overweight, have heart disease, high blood pressure, or respiratory disease), are 65 years of age or older, or you take medications that may be affected by extreme heat. Also, you may be more susceptible to heat if you have skin diseases or rashes.
Heat stress puts workers at risk for illnesses such as heat cramps, heat syncope, heat exhaustion, and heat stroke. Heat can also lead to accidents resulting from the slipperiness of sweaty palms, and from accidental contact with hot surfaces. As a worker moves from a cold to a hot environment, fogging of eye glasses can briefly obscure vision, presenting a safety hazard. The first step in preventing them is learning more about heat illnesses and how they can impact your health.
Heat cramps are sharp pains in the muscles that occur when there is a salt imbalance in your body from not replacing salt lost with sweat. Cramps occur most often when you drink large amounts of water without enough salt (electrolyte) replacement. You may experience heat cramps alone or combined with one of the other heat stress illnesses.
Heat syncope occurs when you feel dizzy, light headed or faint suddenly and lose consciousness due to low blood pressure. It can be caused by blood pooling in the legs if you have been standing still for a long time in a hot environment, or by the loss of body fluids through sweating. Your risk of developing heat syncope increases when you have not adjusted (acclimated) to a hot environment or are dehydrated. Resting in a cool area usually brings about a quick recovery.
Heat exhaustion is caused when you lose body water and salt through excessive sweating. Signs and symptoms of heat exhaustion include: heavy sweating, weakness, dizziness, visual disturbances, intense thirst, nausea, headache, vomiting, diarrhea, muscle cramps, breathlessness, palpitations, tingling and numbness of the hands and feet. People usually recover after resting in a cool area and drinking cool salted drinks (e.g. sports drinks).
Heat stroke and hyperpyrexia (elevated body temperature) are the most serious types of heat illnesses and require immediate first aid and medical attention. Signs of heat stroke include body temperature of more than 41°C, and complete or partial loss of consciousness. The signs of heat hyperpyrexia are similar except that your skin remains moist. Sweating is not a reliable symptom of heat stress because there are two types of heat stroke - "classical" heat stroke where there is little or no sweating (usually occurs in children, the chronically ill, and the elderly), and "exertional" heat stroke where body temperature rises because of strenuous exercise or work and you do sweat.
Heat stroke can cause death or permanent disability if emergency treatment is delayed or not given.
Prevention tips for employers
Every year, Canadian workers die on the job because of heat-related causes. As an employer you must manage this risk - evaluate the situation and determine appropriate controls. Depending on the workplace, a heat stress control program may be necessary. You can help reduce the risk by managing work activities so that they match the employee's physical condition and the temperature.
Provide training. Take time to train your workers on the serious health risks of heat illness, how to avoid it, how to recognize the symptoms and what to do if it happens.
Keep workers cool and hydrated. Demonstrate your commitment to worker health by allowing some flexibility in work arrangements during hot conditions. If possible, schedule heavy tasks, and work that requires personal protective equipment, for cooler times such as early mornings or evenings. Keep the work area cool, or provide air-conditioned rest areas. For workers on duty in the heat, provide plenty of water and encourage them to drink even if they don't feel thirsty, and to take frequent rest breaks.
Prevention tips for workers
Acclimate. Do not expect to tolerate the heat right away. It can take up to two weeks to build up a tolerance (acclimate) to working in hot conditions. Adapt your work and pace to the temperature and how you feel.
Take breaks. A simple but potentially life-saving practice, taking a break to cool off in the shade or in an air-conditioned building or vehicle helps prevent your body from overheating. If you don't have a shady or cool place, reduce your physical efforts.
Keep cool. Stay out of the sun as much as possible. If your job includes some physically demanding tasks, try to save those for the early morning or late afternoon hours when the sun is less intense. Wear lightweight clothing and a hat. The risk of heat illness can be greater if you wear certain types of personal protective equipment. If necessary, consider also wearing a cooling vest to help keep your body temperature down.
Stay hydrated. This is essential. As a general guideline, drink one cup of water every 15 to 20 minutes, whether you are thirsty or not.
Avoid alcohol and drugs. They can worsen the effects of heat illness. If you are on medication, read the label or talk to your doctor to understand how it might cause your body to react to the sun and heat.
Recognize the symptoms of heat stress in yourself and your co-workers. These symptoms include rash, cramping, fainting, excessive sweating, headache and dizziness. You may not see or feel the effects so always use the buddy system to monitor one another.
Heat illness is a serious but easily preventable health risk.
More information on heat illness:
Hot Environments - Health Effects, CCOHS
- Fast Facts: Protecting Yourself from Heat Stress PDF, NIOSH
Working in Hot Environments Health and Safety Guide, CCOHS
Keep Your Cool poster for outdoor workers, CCOHS
Tips & Tools
What do cashiers, assembly line workers and healthcare workers have in common? They work in occupations that have them standing for long periods of time, or working in hazardous areas, all which can take a toll on feet and increase the risk of foot injury. Feet can get hurt, punctured, crushed, sprained, and lacerated. A lack of attention to foot safety can also cause slips, trips and falls.
Feet don't just get hurt while in motion - they also can be injured when standing in one place for too long. The human foot is designed for mobility. Continuous standing not only tires your feet but can cause the joints of foot bones to become misaligned. It can even cause inflammation that might later lead to rheumatism and arthritis.
Wearing the wrong footwear can cause blisters, calluses, corns, arthritis, toe malformations, fallen arches, bunions and other problems.
However, there are things you can do to reduce foot problems and injuries in the workplace such as keeping your feet healthy, and identifying relevant hazards. Start with these factors:
Tasks should incorporate varying body positions that use different muscles. Job rotation, job expansion and teamwork, as well as frequent short rest breaks, can all help reduce the toll on your feet
A workstation should allow you room to change body position. A foot-rail or footrest allows you to shift from one leg to the other when standing and reduces stress on the lower legs. Where possible, a worker should be able to work sitting or standing at will. And even when work can only be done while standing, a seat should be provided for resting purposes.
An unyielding floor, such as concrete, has the impact of a hammer on the feet when stepped on. Any other type of floor is preferable - wood, cork, carpeting, or rubber. As a last resort, anti-fatigue matting provides cushioning that reduces foot fatigue, but should be used with caution (see OSH Answers to read about the limitations of matting).
When choosing footwear, look for the following qualities:
- inner side of the shoe must be straight from the heel to the end of the big toe
- shoe must grip the heel firmly
- must be roomy enough for the toes to move freely
- must have a fastening across the instep to prevent the foot from slipping when walking
- must have a low, wide-based heel; flat shoes are recommended
- must fit properly as it may not stretch
- shock-absorbing insoles to help cushion the foot from impact
For workers exposed to foot hazards, protective footwear is essential to ensure safe and healthy feet. Safety shoes and boots protect your feet, help prevent injuries to them, and reduce the severity of injuries that do occur in the workplace. All jurisdictions in Canada require that workers wear adequate protection against workplace hazards. For workers exposed to foot hazards, the required protection is protective footwear certified by the Canadian Standards Association (CSA Standard "Protective Footwear", CAN/CSA-Z195-09). Ensure that your protective footwear conforms with the appropriate standard for your jurisdiction. All working footwear, for both men and women, whether it is safety wear or not, should provide comfort without compromising protective value.
Feet are subject to a great variety of skin and toenail disorders. You can avoid many of them by following simple rules of foot care:
- Wash your feet daily with soap and dry them thoroughly, especially between the toes.
- Trim toenails straight across and not too short. Do not cut into the corners.
- Check your feet frequently for corns, calluses, and cracks.
- Wear clean socks or stockings and change them daily.
Some feet sweat more than others and are more prone to athlete's foot. Again, following a few simple guidelines may help:
- Select shoes made of leather or canvas, not synthetic materials.
- Keep several pairs of shoes on hand and rotate shoes daily to allow them to air out.
- For some workers, non-coloured woollen or cotton socks may be recommended since dyes may cause or aggravate skin allergies.
- Use foot powder.
- If problems persist, see a doctor or health care specialist.
In cases of persisting ingrown toenails, calluses, corns, fungal infection and more serious conditions such as flat feet and arthritis, see a doctor and follow the doctor's advice.
Foot Comfort and Safety at Work, OSH Answers fact sheet, CCOHS
Safety Footwear, OSH Answers fact sheet, CCOHS
Foot Health, Canadian Podiatric Medical Association
Health Canada is seeking written comments from all interested parties on a proposal to repeal and replace the Controlled Products Regulations, and make consequential amendments to related regulations, to implement the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in Canada.
The implementation of the GHS through the proposed regulatory amendments is intended to achieve the Canada-United States Regulatory Cooperation Council commitment to align and synchronize implementation of common classification and labelling requirements for workplace hazardous chemicals within the mandate of Health Canada and the United States Occupational Safety and Health Administration.
The proposed regulatory amendments would support the Government of Canada in facilitating international trade through common labelling and other hazard communication requirements; lowering costs for businesses and consumers by reducing the need for re-testing and re-classifying chemicals from, or for, different markets; and increasing worker protections through the adoption of a globally recognized standard for communicating the hazards associated with workplace chemicals.
In addition, amendments are being proposed to the Hazardous Materials Information Review Regulations and the Hazardous Materials Information Review Act Appeal Board Procedures Regulations to reflect amendments to the Hazardous Materials Information Review Act that came into force on April 1, 2013, as a result of the Jobs and Growth Act, 2012.
This Notice is an opportunity for the public to provide early comments and input into the proposed regulatory amendments before the regulations are prepublished in the Canada Gazette. The prepublication process will provide an additional opportunity for public consultation on the proposed regulations.
The proposed regulatory amendments will be made available to the public through Health Canada's Web site at www.hc-sc.gc.ca/ewh-semt/consult/_2013/ghs-sgh/index-eng.php.
You have until September 15, 2013 to provide your comments on the proposed regulatory amendments, in writing, to the address provided below.
Questions and requests for additional information, as well as comments on this Notice and the proposed regulations, may be directed to the Workplace Hazardous Materials Directorate, Health Canada, 427 Laurier Avenue W, 7th Floor, Ottawa, Ontario K1A 1M3, 613-993-9167 (telephone), 613-993-5016 (fax), email@example.com (email).
Health and Safety To Go
This month's Health and Safety To Go! podcasts discuss workplace chemical inventories, and feature an encore presentation on car seat ergonomics.
Feature Podcast: Workplace Chemicals - Know What's in Store
It is essential to know what chemicals you have in your workplace. A chemical inventory is a fundamental piece to your chemical safety program and is your first step towards chemical safety compliance - whether it's WHMIS training, environmental reporting, or emergency planning. This podcast discusses how to create a workplace chemical inventory program or take steps to improve an existing one.
The podcast runs 3:48 minutes. Listen to the podcast now.
Encore Podcast: Car Seat Ergonomics
Dhananjai Borwankar, Technical Specialist at CCOHS explains how drivers can adjust their car seats to ensure proper posture and eliminate pains and strains while driving.
The podcast runs 8:45 minutes. Listen to the podcast now.
CCOHS produces free monthly podcasts on a wide variety of topics designed to keep you current with information, tips, and insights into the health, safety, and well-being of working Canadians. You can download the audio segment to your computer or MP3 player and listen to it at your own convenience... or on the go!
See the complete list of podcast topics. Better yet, subscribe to the series on iTunes and don't miss a single episode.
New poster has tips to help you safely work outdoors
Working outdoors in the summer may conjure up images of sunshine and warmth, but the soaring temperatures, humidity and poor air quality also increase the risk of dehydration, harmful UV radiation, and heat-related illnesses.
Display this new poster from CCOHS packed with safety tips for workers who take it outdoors in the sun and extreme heat. Drink up, acclimatize, cover up, shield yourself, time your tasks right, and take breaks so you can keep it cool all summer long.
You can download a free PDF or purchase double-sided - English on one side, French on the other - full-color 16" x 25" copies.
Learn more about the poster.
See all posters from CCOHS.
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The Health and Safety Report, a free monthly newsletter produced by the Canadian Centre for Occupational Health and Safety (CCOHS), provides information, advice, and resources that help support a safe and healthy work environment and the total well being of workers.
© 2016, Canadian Centre for Occupational Health and Safety
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