Planning for High Temperatures and Poor Air Quality in Summer Months

Prepare Your Team to Prevent Heat Stress and Air Quality Effects

Summer Months Bring Increased Risk

Preventing heat stress requires more than sunscreen and water bottles. To keep your teams safe this summer, it’s important to understand the causes, symptoms, and mitigation methods for heat-related illnesses on the job.

While risks for outdoor workers are greatest, there are also hazards for indoor workers in industrial settings. Especially in warmer weather, radiant heat can build indoors in metal shops, warehouses, and any confined indoor space with poor ventilation, leading to life-threatening conditions.

Outdoor air quality is also worsened in the summer months, exacerbating the effects of heat and aggravating conditions like asthma. Especially as Canada’s wildfire season has been consistently lengthening in duration and increasing in intensity and number of fires, pollution from particulate matter is causing severe air quality concerns.

The good news is that proper protocols, gear, and prevention education can significantly reduce the impacts of high temperatures and poor air quality, keeping your teams safe and your workplace efficient.

Effects of Wildfires on Canadian Air Quality

With wildfires blazing across the country, it’s imperative for workplaces to understand the impact of the resulting pollution.

•   Due to the prevalence of mining operations in the country, toxic metals are surfaced and spread in wildfire smoke. Arsenic, a known carcinogen, is especially dangerous, especially for groups already at higher risk for certain cancers.

•   Wildfire smoke also contains PM 2.5, a microscopic particulate matter that settles deep inside human lungs. It can aggravate respiratory conditions like asthma and COPD, and raise risks of cardiac arrest by up to 70 percent, according to a study published in the Journal of the American Heart Association.

•   Other effects of inhaling wildfire smoke include exposure to other toxic materials and microplastics.

•   Smoky air reduces oxygen delivery to your bloodstream and triggers immune responses that can cause body-wide inflammation.

•   Mild symptoms (manageable onsite): eye irritation, runny nose, sore throat, light cough, mucus, wheezing, headaches

•   Severe symptoms (seek immediate medical care): shortness of breath, severe cough, dizziness, chest pain, heart palpitations

•   Smoke exposure also increases risk of infections like pneumonia and COVID-19

Consider supplying your outdoor crews with easy-to-use, disposable N95 respirators when air quality is poor, and keep an eye on proximity to wildfires. Monitor workers for signs of respiratory issues, and encourage frequent breaks.

What Temperature Is Unsafe for Work?

There is no single set temperature threshold for unsafe working conditions. Rather, employers should monitor multiple aspects of exertion, temperature, and worker safety that, combined, can contribute to heat stress.

The Canadian Centre for Occupational Health and Safety (CCOHS) recommends assessing based on the web-bulb globe temperature, which represents the total temperature effect on people that includes air temperature, humidity, wind, and radiation.

Use the following as a guideline for temperature responses:

Temperature-based requirements can vary by province as well. Check here to see what specific workplace temperature regulations exist for your local sites.

What Are the Risk Factors for Heat Stress?

Temperature is just one element of heat stress. There are two broad categories of risk factors: workplace and personal.

This graphic from Employment and Social Development Canada (ESDC) illustrates how risk factors coincide to lead to heat-related illness.

Heat stress for workers comes from both environmental factors and the internal heat generated by performing physical labor. It’s important to account for both when considering heat stress factors.

How to Spot Sun Stroke Symptoms and Heat Exhaustion

Spotting sun stroke symptoms and indicators of heat exhaustion isn't always easy. Heat-related illnesses often progress in stages, with early signs that can be overlooked if your team isn’t properly trained to recognize them. Learning to address these nascent stages is crucial. Here are symptoms to look out for:

•   Heat rash and cramps: Itchy red skin or muscle spasms are early indicators of heat stress. Don’t ignore them, as they’re often a precursor to more serious symptoms.

•   Heat exhaustion: Heavy sweating, fatigue, nausea, dizziness, and a rapid pulse signal that the body can’t keep up with heat output. Core temperatures may reach up to 40°C.

•   Heat stroke: Confusion, dry skin, slurred speech, and unconsciousness indicate a medical emergency. Core temperature exceeds 40°C, and urgent cooling is critical.

For a comprehensive framework for assessing heat-stress risk, check out this resource from ESDC.

Surprising Causes of Heat Stroke and Other Illnesses

Heat-related hazards may be less noticeable than you think. Many Canadian work environments generate significant thermal stress even when the temperature outdoors seems bearable. By understanding these less apparent risks, you can take action to prevent heat-related health issues before they emerge.

Insulation from personal protective equipment

When workers are required to wear heavy PPE, such as welding gear or flame-resistant clothing, heat can become trapped, reducing the effectiveness of sweat evaporation. To combat this, consider moisture-wicking clothing options like Chill-Its® cooling arm sleeves or lightweight cooling vests. These options allow for better heat management while offering necessary protection.

Indoor spaces with limited ventilation

In facilities like warehouses, mines, or processing plants, poor airflow can create conditions similar to a greenhouse. The addition of radiant heat from machinery or lighting can exacerbate the situation. A portable fan can significantly improve air circulation and help manage temperature discomfort in these settings.

Confined environments

Spaces like manholes or tanks can trap both heat and humidity, increasing the risk of dehydration and heat-related illness for workers. These areas necessitate regular check-ins and breaks to allow cooling off and recovery.

Sudden temperature changes

Employees transitioning between hot factory environments and cold-refrigerated areas face the risk of thermal shock. These abrupt temperature shifts can lead to muscle cramps or even hypothermia. Caution and gradual transition strategies can help mitigate these risks.

Lack of shade in outdoor work zones

Outdoor staging areas should be equipped with shaded hydration and rest stations to ensure worker comfort and safety. Where natural shade is unavailable, a durable pop-up tent can provide temporary relief, letting team members cool down before returning to work.

Best Practices to Prevent Heat Stress

Combatting heat-related sickness at work is best achieved through a comprehensive system: maintaining hydration, adjusting to conditions, managing work-rest cycles, and utilizing appropriate tools all contribute to employee safety.

Drink water regularly, even when not thirsty

The Canadian Centre for Occupational Health and Safety suggests that during intense heat, employees should consume about 250 ml of water every 15 to 20 minutes. Urge gradual sipping rather than rapid intake, and provide electrolyte solutions to replenish minerals lost in sweat, such as sodium and potassium. Lawson's Qwik Stik® Mix and Sqweeze® Freeze Pops offer affordable and effective hydration support on-site.

Create an acclimatization strategy

Avoid immediately assigning full shifts to newcomers or returning employees. Follow guidelines that recommend starting with 20% exposure on the first day, increasing by 20% daily until the complete workload is achieved. Ensure regular short breaks in shaded, cool environments to aid the body's adaptation.

Provide resting spaces with shade and airflow

Establish specific cool-down zones with shade, fans, and cold water availability, enabling workers to recuperate and lower their heat stress risk. For those who must stay on-site, wearable cooling solutions like the Chill-Its Evaporative Hard Hat Cooling Pad offer quick, comfortable relief for several hours, designed to fit most safety helmets and easily reactivated with water.

Educate and document heat safety procedures

Training is crucial. Make sure your team members can identify and react to signs of heat illness and know the proper emergency procedures. As regulations around heat safety evolve, a formalized heat safety protocol and documented training will become increasingly important.

While there is currently no national standard for workplace heat stress plans in Canada, Ontario passed the Heat Stress Act in 2025, which requires employer documentation of heat safety, including written policies, documented assessments, training, and annual review. As global warming impacts Canada at twice the average rate of other countries, other provinces may soon follow Ontario’s lead.

Focus on Heat Stress Prevention This Summer

Heat illness can significantly slow down your operations — and more importantly, put a drain on worker safety and morale. As summer continues, there’s no better time to assess your worksites and ensure that everyone works together to prevent heat stress and other illnesses.

For more in-depth guidance, explore:

•   ESDC’s Thermal Stress in the Workplace resources

•   OHCOW’s Heat Stress Toolkit

•   CCOHS’s Hot Environment guidance

Need support to create a cooling strategy for your team?

Lawson Products can help. With hydration solutions, cooling PPE, and portable jobsite gear, we offer everything you need to stay compliant and keep your crew moving forward, safely.

Talk to your Lawson representative today to create a custom heat safety plan that works as hard as your team does.

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