Each year thousands of workers across the nation become ill when exposed to excessive heat. Approximately 50 to 70 percent of heat illness cases happen during the first few days of working in warm or hot weather. Some examples of heat illness include heat stroke, heat exhaustion, and heat rash.

Heavy activity, lack of time to adjust to the new conditions, or wearing clothes that hold in body heat can increase the risk, but heat illness is preventable. If you have employees that work outdoors here are some things you need to provide to help protect them from heat illness:

1. Plenty of drinking water

The water must be:

  • Free of charge
  • As close as possible to where the employee is working
  • Fresh
  • Pure
  • Suitably cool

For proper hydration, plan to provide one quart of water per hour for each employee. For example, a 10-person crew working an 8-hour shift requires 80 quarts or 20 gallons of water (4 quarts per gallon). Use the following formula to determine how much water your crew needs:

Number of people x number of hours worked x 1 quart per hour x .25 (to convert from quarts to gallons) = number of gallons per shift.

If you can’t provide the water all at once, make sure to replenish throughout the day. More importantly, encourage your employees to drink it.

2. Plenty of shade

Employees are allowed and encouraged to take a cool-down rest period whenever they need one. Shade must be as close as possible to where your employees are working and there must be enough shade to accommodate everyone taking a break or rest period. Cool-down rest periods should last at least 5 minutes and it’s important to keep an eye on employees who have visible signs or report symptoms of heat illness and provide First Aid or emergency response if necessary.

If outdoor temperatures are above 80 degrees or if an employee requests it regardless of the temperature, you must have shade available. Buildings or trees can provide shade for your workers. Use pop-up canopies or shade trailers if natural shade is not available.

3. An emergency plan

If an employee displays symptoms of heat illness, they need help right away. Coworkers should be ready to act immediately. Some of the steps they can take include:

  • Calling for emergency medical response
  • If in a remote area, sending someone out to the entrance to guide the emergency crew when it arrives
  • Monitoring the affected worker and providing assistance, such as First Aid, helping them cool off, elevating feet, loosening heavy clothing, etc.
  • Helping them find shade and water
  • Notifying management of the situation

4. A plan to help your employees adjust to the conditions

It takes about 14 days for workers to adjust to the heat and it is important to train employees on how to do that. Below are steps you can take to help your employees get used to the heat:

  • Reduce workload or shift length.
  • Gradually increase the duties as employees get used to the conditions.
  • Remind employees to wear loose-fitting, lightweight clothing unless they're working near heavy machinery.

During a heat wave, monitor all employees—especially new staff, those returning from extended leave, and those moving to the area from a cooler climate.

5. Heat illness prevention training

If there is a risk of heat illness, all employees must be trained before they begin working. The training needs to be specific to your heat illness plan and procedures. Training should cover the following:

  • How your employees can recognize heat illness symptoms in themselves and in coworkers.
  • Which environmental factors are present at your workplace, e.g. temperature and humidity.
  • What the different types of heat illness are.
  • How to execute your emergency plan, including First Aid, as referenced above.

6. A written heat illness prevention plan

Having a heat illness prevention plan is not only important for the health of your employee; it’s also required by law. The plan must be in writing in both English and the language understood by the majority of your employees. The plan must be made available at your workplace and outline specific procedures for providing:

  • Sufficient water
  • Access to shade
  • Emergency response
  • Adjusting to the heat
  • Training

Some industries are required to implement high heat procedures when temperatures reach or exceed 95 degrees. These procedures include providing increased monitoring of all employees for alertness and heat illness symptoms, conducting a pre-shift meeting to review the signs and symptoms of heat illness, and requiring employees to take a minimum 10-minute preventive cool-down rest period every two hours. Even if your industry isn’t covered by these high heat requirements, consider using these procedures.

Working in the heat takes a toll on your workers. Help them stay safe by reviewing your heat illness prevention plan at your next safety meeting.