Preventing Heat Stress In The Workplace

As many places in Canada are sweltering under a summer heat wave, employers should assess the risk of heat exposure in their workplace and, where appropriate, develop and implement workplace policies to reduce the risk of illness or injuries relating to heat stress. Most Canadian provinces have enacted specific regulatory requirements to combat thermal stress arising from extreme heat or cold. However, even in those provinces where no specific regulatory requirement exists relating to thermal stress (for example, like in Ontario and Alberta), an employer still has an obligation to prevent heat stress in the workplace as part of its general duty to protect the health and safety of its workers.

Although a number of manufacturing activities can expose workers to heat year-round, incidents of workplace heat exposure and heat stress clearly increase in the summer, particularly where employees are engaged in outdoor work activities. If there is a risk of excess heat exposure in the workplace, an employer is well-advised to take the following steps to prevent heat stress:

Train supervisors and workers to recognize early signs and symptoms of heat stress in themselves and their co-workers, including excessive sweating, dizziness and nausea

Where working in hot environments, arrange work schedules to permit employees to become acclimatized to heat

Provide adequate supervision and don’t allow individuals to work alone in conditions where heat stress is a legitimate risk

Determine appropriate work-rest cycles that allow time for workers to cool down

Provide shaded or well-ventilated areas for breaks and rests and, where appropriate, reduce temperature and humidity through air conditioning

Schedule more physically demanding work at cooler times of the day and, where possible, rotate work activities to reduce heat exposure

Make cool drinking water available and remind workers to drink water regularly to stay hydrated (i.e. approximately 250 mL of water every 20 minutes)

When working outdoors, remind workers to wear light-coloured, loose-fitting clothing that is breathable

Encourage workers to wear long-sleeved shirts and pants and keep their heads covered to reduce direct exposure to the sun when working outdoors

If you suspect that a worker is suffering from heat stress, move him or her to a cool, shaded area, provide the worker with water and appropriate first aid

There are a number of helpful on-line resources to help employers develop workplace policies and programs to combat heat stress in the workplace. For more information on preventing heat stress in the workplace, employers are encouraged to take a look at the following publications:

Ontario Ministry of Labour – Heat Stress Guideline –

Ontario WSIB – Guide to Preventing Heat Stress –

WorkSafe Alberta – Best Practices for Working Safety in the Heat and Cold –

WorkSafe BC – Preventing Heat Stress at Work –

Québec – CSST – Guide de prévention des coups de chaleur –

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Blair McCreadie

About Blair McCreadie

Blair McCreadie is the Managing Partner of the Toronto office of Dentons Canada LLP and is a member of the firm’s National Management Committee. Blair also practices in the firm’s Employment, Labour & Pensions practice group, where he works in partnership with employers to meet the full range of their corporate human resources needs, including strategic employment and human rights advice and management-side labour relations.

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