May 13, 2004

HEAT STRESS IN THE WORK PLACE ADVISORY

As temperatures reach 30 degrees Celsius, Ontario’s Occupational Health clinics are reminding employers and employees of the dangers posed by the high heat and humidity and urging them to take precautionary actions to prevent heat related illnesses and even death.

“Ontario workers need to be aware that exposure to high temperatures and humidity can be very dangerous” says Mary Cook, Managing Director of the Occupational Health Clinics for Ontario Workers (OHCOW). “Current weather conditions may cause heat related illness and death and necessary precautions should be taken.”

OHCOW has developed a heat stress advisory system to help people avoid heat strain. The plan specifies what actions need to be taken depending on the Humidex measured in the workplace. 

If the Humidex is 

· 30-33° C: encourage workers to drink extra water; start measuring temperature and relative humidity hourly

· 34-37° C: notify employees that they need to drink more water; ensure workers have received appropriate heat stress training in the last 3 months.

· 38-39° C: provide employees with 15 minutes rest relief per hour; ensure adequate water is being supplied to each employee (at least one cup (8 oz.) of cool water every 20 minutes. Any employees with symptoms should seek medical attention.

· 40-42° C: employees should be provided with 30 minutes relief per hour in addition t the provisions listed for a Humidex of 38-39 C.

· 43-44° C: provide workers with 45 minutes relief per hour in addition to the provisions listed for a Humidex of 38-39 C. If a relief period is not feasible then stop work until the Humidex is 42 C or less.

· 45° C or over: stop work until the Humidex is 44° C or less.

These numbers apply to employees wearing normal summer clothes working indoors and not exposed to any significant amount of radiant heat (ovens, molten metal etc.)

The clinics have produced a poster (download a copy) for the workplace with the details of the Humidex heat response plan and a calculator allowing the conversion of temperature and relative humidity measured in the workplace to Humidex.

For further information contact the clinic nearest you - Toronto, Sudbury, Hamilton, Sarnia and Windsor.