Feeling hot, hot, hot – heat stress prevention

Jun 29, 2011

Feeling hot, hot, hot - heat stress preventionIt’s in the forecast: this summer will be a hot one! That’s good news for vacationers, a warning bell for those who will be working through the heat. What better time to develop a workplace heat stress prevention plan? We’ve gathered together some helpful info and tips to get you started, and also spoke with John Oudyk, a heat stress consultant with the Occupational Health Clinics for Ontario Workers (OHCOW), to get the latest news on heat safety. Read this and you’ll be armed with all the info you need to take the next step in keeping this summer safe and healthy for everyone on your crew.

So what is heat stress? It’s a condition that can take many forms, depending on the severity of external and internal factors and of course the condition of the individual. A worker expending large amounts of physical energy in a hot and humid environment, without regular rest or water breaks, may eventually experience heat exhaustion, fainting, heat stroke or heart attack. Long-term, this can lead to reproductive problems, heart and lung strain and other complications, and may even result in death. Professions that often face the threat of heat stress include firefighters wearing heavy protective clothing and equipment in blazing temperatures, outdoor workers working in direct sunlight for extended periods, foundry workers, miners using hot equipment and surrounded by hot rock, as well as bakers lifting and mixing around hot ovens.

Watch for these five symptoms of heat stress:

  1. Heat rash
  2. Syncope or fainting
  3. Heat cramps – muscle spasms in stomach, legs, arms. Remedy: cool down, drink water or electrolyte sports drinks, massage and stretch.
  4. Heat exhaustion – resembles shock (feeling of faintness/nauseated, low blood pressure, skin may be hot and red, victim may have a fever).
  5. Heat stroke – brain cannot regulate the body’s temperature and stops sweating. Body over heats, victim experiences mental confusion and needs immediate medical attention.

If you are aware of these warning signs, heat stress can be prevented. While acclimatization is one solution, it takes seven to 14 days of continuous exposure to heat for the body to adjust to high temperatures. Because extended periods of extreme temperatures are so brief in Ontario, workers don’t have enough time to acclimatize. So instead, workplaces need to proactively prevent heat stress.

The best approach to eliminating heat stress is to prevent the warning signs from happening at all. There are lots of ways workplaces can take measures to ensure their staff is healthy and safe from heat stress, including:

  • Develop, communicate and implement a heat stress plan for all workers. As important as it is to prevent heat stress from happening, it is also important to have a first-aid response system and trained first-aid providers in place in the event it does occur. As well, mechanisms and policies for the recording and reporting of incidents should be developed and made available.
  • Reduce the temperature and humidity through air cooling
  • Provide air-conditioned rest areas or put up shade barriers to block sun heat
  • Increase the frequency and length of rest breaks
  • Provide cool drinking water near workers and remind them to drink a cup every 20 minutes or so.

Oudyk recommends five steps to making your workplace heat stress free:

  1. Provide training on heat stress awareness and prevention
  2. Consider the type of clothing employees wear and if adjustments can be made in hot weather
  3. Set up a thermometer and humidity meter
  4. Measure and monitor the Wet Bulb Globe Temperature (WBGT)
  5. Adjust for radiant heat which intensifies body heat.

Oudyk says the most important way to prevent heat stress is through the evaporation of sweat. Sweating is how the body cools itself but it can be tricky because when the body drips sweat, it’s not as efficient in cooling through evaporation. So the key is to maintain muscular work at a rate where sweat just evaporates, which can mean taking breaks to cool the muscles. Certain types of clothing and fans can also help maximize sweat evaporation.

As for drinking water, Oudyk advises not to wait until you’re thirsty because by that point you’re already dehydrated. Workers should drink water on a regular basis, often more than they expect, even if they don’t feel thirsty.

So who is more prone to heat stress? According to Oudyk, the common assumption is people with lots of risk factors are going to succumb first. In fact, it is usually young males, the least suspected, who end up ignoring their body’s signals. Workers need to listen to their own bodies and take precautions, in addition to the employers’ responsibilities to maintain optimal conditions.

Oudyk says it’s usually the first heat wave of the year that hits the hardest. After long, cold winters, the first heat of the season is a shock to the body as it struggles to balance its internal temperature. Oudyk, who has advocated for heat stress prevention for over 20 years, says that heat stress is often underreported in Ontario. Incidents are blamed on the weather, not the workplace. Organizational first aid reports during initial heat waves often show a more accurate picture, with considerable increases in first aid visits.

The member health and safety associations of Health & Safety Ontario provide resources and training to help clients maintain healthy, safe workplace environments. To find out how you can beat the heat and prevent heat stress, visit the Heat Stress topic page, where you will find information, training, products and free downloads.

WSPS resources include:

External resources include: