Handling Heat Dangers While Working Outside

Now more than ever it's vital to be aware of how to work safely outside and avoid potential dangers like heat stroke

Handling Heat Dangers While Working Outside

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The summer has been a hot one so far. Even for areas accustomed to heat, some of the temperatures and heat index levels have been particularly extreme.

And those working in a construction-related field are some of the most at risk of suffering heat-related illness. To guard against things like heat stroke and even heat exhaustion, companies need good planning, even better training, and the best work practices, protocols, and products that make it safer to work hard in the heat.

Planning and preparation

When it comes to preventing heat illness in workers, OSHA says employers have certain responsibilities. For instance, companies must provide ample water and allow for adequate rest periods in the shade.

The National Institute for Occupational Safety & Health has developed a sample work/rest schedule for workers wearing normal clothing. For example, a worker performing heavy work, such as climbing or using hand tools for extended periods, in 95 degrees F temperatures should work for 45 minutes and rest for 15. A worker performing heavy work in 104 degrees F temperatures should work for 20 minutes and rest for 40. A worker performing light work, such as operating equipment, can maintain a normal schedule until the temperature hits 106 degrees F. But keep in mind that adjustments will likely have to be made for the types of clothing and PPE workers must wear, along with the amount of direct sunlight, humidity and other factors.

Companies are also encouraged to adopt a practice referred to as acclimatization. This practice establishes a “breaking in” period for new workers and those returning to work after an absence of a week or more. This allows these workers to gradually build up their heat tolerance. OSHA and NIOSH recommend following the 20% Rule, increasing work shift duration by roughly 20% each day until the worker is on the normal schedule. For example, if a worker is expected to work 10 hours a day:

  • Day 1 – 2 hours
  • Day 2 – 4 hours
  • Day 3 – 6 hours
  • Day 4 – 8 hours
  • Day 5 – 10 hours

In some instances, the acclimatization period may take longer than five days. It’s important to monitor each worker’s performance and maintain open communication as to how they are adapting.

Once a “new” worker is ready for a normal work routine, the monitoring and open communication cannot stop. The intense physical demands of working in construction make things very unpredictable when working in extreme heat. A popular tactic is to establish a buddy system. New workers in particular should not be left completely on their own. Companies must also make it clear that heat stress is taken seriously by senior leadership, and that a worker should never feel hesitant about reporting symptoms to their supervisor.

For new and experienced workers alike, companies should also develop a broader heat illness prevention plan. The plan should cover the following topics in specific detail:

  • Who will provide heat stress training and oversight, and how and when?
  • What work practices and controls will be put in place to help protect workers?
  • How will heat stress be monitored and measured on the job site?
  • What protocols are in place for when a worker falls victim to heat stress?


The training piece is very important. Both workers and supervisors must understand how serious heat-related illnesses can be, and how to go about preventing them on the job site.

Training must begin long before the hot outdoor work begins. Then, when the heat is on, morning meetings are the ideal time to reaffirm the company’s commitment to safety and to continually remind employees about the work practices and protocols designed to keep people safe in the heat. Supplemental training tools like emails, social media posts, posters and other training resources can help keep heat safety top-of-mind with employees.

Key topics to be included in a robust heat stress training initiative include:

  • Types of heat-related illness
  • How to recognize common signs and symptoms
  • Importance of immediately providing first aid
  • Procedures for contacting emergency medical services
  • Importance of protecting new workers
  • Fluid replacement guidelines
  • Appropriate work/rest cycles
  • Proper use and care of heat-protective clothing and PPE
  • Effects of other factors on heat stress, i.e. drugs, alcohol, obesity

Supervisor training could also include the following:

  • Monitoring weather reports
  • Responding to hot weather advisories
  • Ensuring that workers follow policies regarding hydration and rest periods

Adapting on the job site

Along with some of the training tips already discussed, the CDC offers additional advice to employers on how they can help control heat stress. This is obviously harder for companies that work outside. Nonetheless, several recommendations have some merit when it comes to construction companies. For example:

  • Use tools and equipment designed to minimize manual strain
  • Increase the number of workers per task
  • Look for ways to use cooling controls like fans and misting fans
  • Offer personal cooling devices like cooling bands and helmet inserts
  • Provide adequate amounts of cool, potable drinking water near the work area
  • Encourage workers to drink often

Hydration is a critically important aspect of staying safe on a hot job site. Generally speaking, construction workers should drink at least 8 ounces of cold water every 15 to 20 minutes. In extreme heat when perspiration accelerates even more, electrolyte-infused drinks that are low in sugar and caffeine can be very helpful, if not necessary.

Regardless of how well-planned and executed a company’s heat illness prevention efforts are, it is still possible that a worker may fall victim to heat stress. It’s essential that all workers on a job site, not just the supervisors, are trained on how to recognize various heat stress symptoms. For instance, heat exhaustion symptoms include fatigue, irritability, thirst, nausea/vomiting, dizziness, heavy sweating, higher body temperature and rapid heart rate. Heat stroke symptoms include confusion, slurred speech, seizures, unconsciousness, heavy sweating or hot/dry skin, high body temperature and rapid heart rate.

Other signs to watch for are muscle weakness, pain or cramps, heat rash and dark urine.

Whenever any of these symptoms are observed, first aid should be promptly administered. To ensure that happens, emergency response protocols must be detailed in the company’s heat illness prevention plan. That includes who on a job site will be tasked with administering first aid and making sure that individual(s) is properly trained to the OSHA Standard.

The core principles of heat illness-related first aid include: 

  • Take the affected individual to a cooler area, whether an air-conditioned trailer or at least in some shade
  • Remove outer layers of clothing
  • Place ice or cold towels on the head, neck, trunk, armpits and groin
  • Immerse in cold water or an ice bath, or cool with a fan
  • Remain with the affected individual while they are being treated

First aid providers shouldn’t waste time trying to diagnose which heat-related illness an employee may be suffering from. Some of the symptoms overlap, and sometimes multiple heat-related illnesses could be happening at the same time. Regardless, the key is starting first aid as soon as possible. And when in doubt, call 911 — particularly if signs of heat stroke are observed.

When it comes to heat stress in the construction industry, there is simply no time to waste. The sooner a company makes a top-down commitment to heat stress safety, the better its heat illness prevention planning will be — and the better off workers will be, no matter how hot it gets.

About the author: AEM is the North American-based international trade group representing off-road equipment manufacturers and suppliers, with more than 1,000 companies and 200-plus product lines in the agriculture and construction-related sectors worldwide. AEM has an ownership stake in and manages several world-class exhibitions, including CONEXPO-CON/AGG.


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