Getting accurate temperature measurements in the workplace

As summer brings higher temperatures, the workplace temperature can rise to an uncomfortable level. This can adversely effect the health of your workers, but also their productivity and the quality of the products you manufacture. On really hot days, employers are legally required to take protective measures. But how to get accurate temperature measurements in the first place?

Achieving accurate measurements: using the WBGT method

To accurately take temperature measurements in the workplace, using a standard thermometer simply won’t do. Instead, you should use a wet bulb globe thermometer, a measurement tool that takes into account ambient temperature, humidity and heat radiation from other sources. The Wet Bulb Globe Temperature or WBGT value is then calculated based on those criteria.

When is it too hot to work?

The occupational health physician determines the workload level of employees. Each physical workload level corresponds with a maximum wet bulb globe temperature, and whenever this value is exceeded, the employer must take action.

By carrying out a workplace risk assessment, you can estimate when the WBGT value will be exceeded. The risk analysis must take into consideration factors such as the orientation of the building, the number of windows and any ventilation systems that may be in use.

Tips on keeping a cool head

Legal requirements when the workplace experiences excessive heat:

  • Offer refreshing drinks for free.
  • Allow for additional rest periods.

Optional: implement a heat plan

  • Wearing appropriate clothing can make all the difference. Provide a lighter weight and looser weave alternative if your workers require a uniform.
  • Switch off as many electrical appliances as possible, as they all emit heat.  
  • Schedule tasks according to the weather to ensure that strenuous (physical) tasks are carried out in the morning or late at night. Or simply delay these tasks until the weather cools down.
  • Allow your workers to start work earlier and adjust their work roster.
  • Install a ventilation system, but don’t set the air conditioning too high as this will alter the heat balance inside the building and reduce the efficiency of the air conditioning system.  
  • Paint the roof of the building white. This will reflect the sunlight and keep the building cooler for longer.   
  • Keep sun blinds closed as a preventive measure to stop the room from heating up from the moment the sun rises.   

Above all, use common sense. Be more understanding when things slow down a little during a heatwave, even when the official WBGT value has not been exceeded.

Use an online heat stress calculator to determine the WBGT value at work. Keep in mind that the WBGT value can vary from room to room within a building and that the results of the online calculator should be used as an indication only.