Prepare for heat stress now. It's just a matter of time

May 09, 2014

heat stressBack in January hot weather seemed a long way off, but it's coming. And more of it every year. The number of extremely hot days has been increasing globally over the past 15 years, a recent study has found.1

These heat waves may last only a week or two, but in this time workers can suffer debilitating effects and even death. A few simple steps taken now can keep your people thriving and productive even in the hottest weather.

"In my view, everyone has a critical part to play," says WSPS occupational hygiene specialist Susan Ing. "Employers set the parameters, but when extreme heat arrives it's the supervisors and workers who are best placed to protect each other." Here's a 10-step plan for mobilizing everyone.

Steps for employers

1. Put a policy and procedures in place. "It doesn't have to be detailed," says Ing. "For instance, create a response plan that pairs specific humidex temperatures with preventive measures, and map out what you want supervisors to do in such a way that they can actually do something. Don't say 'Wear appropriate…' Be specific."

2. Train all employees during orientation on the policy and procedures. Include heat stress symptoms, how to prevent it, and what to do if someone starts showing symptoms. Heat stress training is particularly critical for young and new workers. Research conducted by the Institute for Work & Health shows that heat strokes, sunstrokes and other heat illnesses disproportionately affect those on the job less than two months2. Workers with certain medical conditions are also extremely vulnerable, warns Ing.

Steps for supervisors

3. Acclimatize workers to hot conditions, and watch out for de-acclimatization. Workers can lose their tolerance in only four days.

4. Schedule work in the hottest locations for cooler times of day. Build cool-down breaks into work schedules. Adjust the frequency and duration of breaks as needed. "Taking a break means going to a cooler work area or providing workers with periodic rest breaks and rest facilities in cooler conditions."

5. Get to know your workers. "Keep your eyes and ears open: 'Is so-and-so looking a little different from how he normally looks? A little more flushed? Sitting down more?'"

6. Ensure ready access to cool water in convenient, visible locations.

7. Supply protective equipment and clothing as needed, such as water-dampened cotton whole-body suits, cooling vests with pockets that hold cold packs, and water-cooled suits.

8. Monitor weather forecasts. "If it's Tuesday and you know superhot weather is coming on Thursday, ask yourself, 'Who will be working then? What will they be doing? Who should I watch out for?'"

9. Be extra vigilant in extreme conditions. "Check on workers frequently. If you can't do this, then assign a temporary pair of eyes to do it for you."

Steps for workers

10. Watch out for each other and speak up. "People suffering from heat stress don't always recognize their own symptoms. If anyone's behaviour is 'more than usual' - more sweating, more flushed, hyperventilating - it could be a sign of heat stress."

Our heat stress resources can help

Everything you need to create a heat stress plan is available on our heat stress resource page:

  • 20-page heat stress awareness guide (including a sample policy, control measures, humidex guidelines, and checklist)
  • humidex-based heat response plan
  • heat stress awareness tool for supervisors to keep on hand
  • heat stress poster.

Check them out today.

1 "No pause in the increase of hot temperature extremes" - Nature Climate Change, 4, 161-163 (2014) - published online on February 26, 2014.


2 The more inexperienced workers are, the study found, the more likely they'll need time off to recover from heat stroke, sun stroke, fainting and other forms of heat illnesses. Read more: Young men in manual occupations are most vulnerable to extreme heat.