As we see summer temperatures soaring higher and higher, heat becomes a greater risk that farmers and landscapers must address. “Heat definitely needs to be managed when people are working outdoors in high temperatures, especially if they are doing physical labour,” says Shawn Chadwick, Industry Partnerships Agriculture Account Manager with WSPS. “And we also have to think about those working inside greenhouses, where temperatures can be 5-30 degrees Fahrenheit higher than the temperature outside.” 

It is important for farm operators to know how heat affects the body, so that they understand how serious the risks are and can effectively communicate this information to their workers. “Heat stress occurs when the body’s cooling mechanisms are struggling to dissipate heat effectively, which leads to a rise in our core body temperature. When your body temperature rises, it can begin to affect other systems in your body,” explains Shawn. 

Recognize the symptoms of heat stress

“Workers need to recognize the signs of heat stress in each other. They should not be ignored,” says Shawn. When someone begins suffering from heat stress, they may experience headache, dizziness, fatigue, blurred vision, heat cramps, heat rash, and excessive sweating. Sometimes it can be difficult to notice these symptoms in yourself, so it is important for everyone to pay attention to each other while working in hot conditions. 

When heat stress progresses to heat exhaustion, people may have symptoms of nausea, vomiting, confusion, and slurred speech. If not treated, heat exhaustion can lead to heat stroke or a heart attack. “When your body’s core temperature has risen over 40 degrees Celsius, you need immediate medical attention,” warns Shawn. “Heat-related illnesses can be fatal.”

Humidity, exertion, and PPE are factors

In many areas of Ontario, humidity is a regular part of summer weather. Most of us are used to checking not only the temperature in the summer months, but also the humidex factor to get a more accurate idea of what it will feel like outside. “Humidex matters because high humidity can impact how quickly our body can regulate its temperature,” says Shawn. “When there is already moisture in the air around us, it becomes more difficult for the body to cool itself through sweating.”

Farm owners, greenhouse operators, and landscapers need to consider the type of work being done and how much exertion is involved when assessing heat-related hazards. Because physical labour generates internal heat, it can exacerbate the situation if the body is already struggling to regulate its temperature. “If possible, save the heavier work for cooler parts of the day,” recommends Shawn.

What you are wearing can make a difference as well. For example, when workers are spraying pesticides, they may be wearing coveralls, gloves, and possibly a respirator or face shield, which can contribute to the body’s temperature. “PPE needs to be considered. Depending on how hot the temperature is outside, and the type of work being conducted, you may need to schedule even shorter shifts with frequent breaks, once an hour and replenishing water lost through sweating even more frequently,” says Shawn.

Prevent heat-related illness

With warmer temperatures coming, anyone who has employees working outdoors needs to do their due diligence by providing training and establishing emergency procedures. “Ensure procedures include frequent rest breaks in a cool area, such as an air-conditioned or shaded space and regular access to water,” says Shawn. “If you feel thirsty, drink water. Do not ignore your body,” he says. 

Provide workers with training on the symptoms of heat-related illnesses, so that they can recognize symptoms in themselves and each other. If you suspect an employee is suffering from heat exhaustion or heat stroke, 

1. Call 911 immediately. If a worker is showing signs of heat exhaustion or heat stroke, they need immediate medical attention.
2. Move the worker to a cooler place. Designate an air-conditioned or heavily shaded area for this in advance, as part of our emergency procedures.
3. Try to lower the worker’s body temperature. Immerse them in or spray them with cool water. Place ice packs on the back of their neck or in their groin area.
4. Monitor the worker’s symptoms. Then you can accurately report them to paramedics when they arrive. 

Support and resources

• Heat Stress Toolkit (OHCOW)
• What is heat stress? Signs and symptoms (video)
• Farm Safety Roundup, Ep 9: The heat is on: Protecting farm workers from the dangers of heat stress (podcast episode)
• Pre-recorded webinar - Safety Connection: Heat Stress
• 5 ways to prevent heat stress (article)
• Signs and symptoms of heat exhaustion (Mayo Clinic)

Training

• Health and Safety by Design: Hazard Reporting and Heat Stress (3.5 hours, online instructor-led training)