A Guide to Heat Acclimatisation
As some organisations around the world implement policies to adhere to new guidelines to protect workers from heat-related illnesses, many are still only learning about the damaging consequences increased temperatures can have on both the worker and the company. With the right understanding, strategy and tools, heat-related illnesses can be prevented. While some regions have guidelines to stop working when temperatures reach a certain level, workers in some sectors, such as metal manufacturing, bakeries, foundries, and offshore oil and gas, do not have this luxury and must continue to carry out their duties at high temperatures.
When the work must continue, heat acclimatisation (also known as heat acclimation) is crucial. An organisation needs to understand the importance of acclimation and implement this within their strategy to mitigate the risk of heat-related injuries, especially during the onboarding process of new employees who are often at the highest risk. Investigations have shown that 80% of the reported cases of heat-related illnesses occurred within the first four days of employment.
In our previous blog ‘Working when the heat is on: How to find your cool’ we explained the process of thermoregulation. While thermoregulation is how our body maintains its internal core body temperature, which is essential for healthy and correct function, acclimatisation can be referred to as a long-term response that enables our body to physiologically accommodate to a new environment. According to NIOSH, heat acclimatisation is the improvement of our body’s tolerance to heat that develops gradually from increasing the exposure to an environment or duration of tasks performed under those conditions.
There is countless research dedicated to the benefits of heat acclimation for athletic performance, but often less when it comes to the workplace. However, when employees are working anywhere from 4 – 8 hours per day in high temperatures and completing strenuous tasks, their exertion levels can be very similar to those of an athlete.
Heat acclimation improves the body’s ability to control core body temperature, improves sweating, increases blood flow through the skin, and expands blood volume allowing the heart to pump more blood to muscles, organs and the skin as needed. This creates less strain on the heart and other vital organs while helping the body to cool faster.
When the body is able to cool better in high temperatures it enhances the employee’s ability to comfortably continue performing the tasks required and decreases their risk of heat-related illnesses.
Sweating is a good example of an individual’s body acclimatising to the conditions as it’s the body’s primary mechanism to cool itself. While sweating may increase, it’s important that employees can easily keep themselves hydrated to replace the fluids lost otherwise this can lead to dehydration, which causes reduced sweating and a strain on the cardiovascular system. It’s good to remember that workers who have acclimatised often need more water rather than less due to increased sweating ability.
As with most new processes, a slow and steady approach is often the most effective; acclimatising employees in the workplace is no different. The most successful results for workers come from gradually increasing the exposure to the conditions over a period of 7 to 14 days and ensuring there is ample time to cool off and rehydrate between shifts.
For new employees, both OSHA and NIOSH recommend the “Rule of 20%” to help them acclimatise effectively. This approach means that new workers should only work 20% of the normal duration in the conditions on their first day and gradually increase the duration by 20% on subsequent days until the employee is performing a normal schedule. While this rule should help keep employees who are physically fit and with no pre-existing medical conditions safe, some employees may require more time to adapt. When it comes to the tasks performed, it is recommended that the employee performs tasks that are similar in intensity to their expected work. Replacing the workload with lighter tasks during the acclimatisation period will not help build heat tolerance to the normal demands of the job. During the process, decrease the duration of the workload rather than the intensity. As the amount of exposure increases, ensure more rest breaks are provided to help recovery.
It’s extremely important to not overdo it in the initial stages; pushing an employee to the point of heat exhaustion and using an incorrect approach will not only limit but will undo any heat tolerance that has been built. If the employer is ever unsure, it is much more effective and safer to allow more days to acclimatise.
While most studies show it can take up to 14 days to become acclimated to a hot environment, the tolerance built up over time can start to dissipate within a few days without exposure to the conditions. It is significantly reduced after 7 days, with the majority of workers returning to their baseline for heat tolerance after 28 days. To maintain heat acclimation employees must have continuous or repeated exposure to the heat; however, working for a day or two in cooler conditions or taking breaks in a cooler environment with air conditioning will not affect the acclimation process.
- Knowledge is power: Train ALL employees on the importance of acclimatisation and how to recognise and report any associated conditions.
- Slow and steady: It is most effective to increase exposure to hot conditions gradually over two weeks while ensuring workers are having ample time to cool off and have a break. Ensure the same workload is applied for shorter periods of time rather than replacing with lighter loads to what is required as this will only acclimatise the employee to the output done. More strenuous activities will require longer for an employee to acclimatise.
- Monitor core body temperature: With the evolution of wearable technology, Bodytrak is a non-invasive solution that allows employers to accurately monitor an employee’s physiological response to workplace stressors, such as increasing temperatures. By implementing a solution that allows an organisation and an employee to understand physiological responses, alerts can be triggered when normal thresholds are exceeded so they can take the necessary precautions and actions to cool down to prevent a serious heat-related incident.
- Keep hydrated: Workers should be provided with access to plenty of cold fluids so that they can maintain hydration. Excessive sweating removes electrolytes from the body that need to be replaced, so drinking isotonic sports drinks as well as water can be extremely beneficial to replace these lost electrolytes. Ensure the team is drinking plenty of fluids throughout the day and not only waiting until they’re thirsty. When the body is dehydrated this will reduce the benefits of acclimation.
- Eat regularly: Similar to isotonic sports drinks, food will also replace electrolytes that are lost while sweating. A large amount of salt is lost when we sweat, especially during the first few days of acclimation. Ensuring workers eat regularly will help restore what is lost in the body.
- Consider PPE in the process: Personal protective equipment (PPE) is designed to protect employees from the external environment while on the job, however, these can often be heavy and contribute to raising core body temperature by trapping heat and preventing cooling from sweating. While PPE is necessary in many organisations it’s important to consider their effects and implement this into the strategy during the acclimation process. When away from any risk and on breaks workers should be encouraged to remove PPE immediately. This will prevent any heat retained in their clothing from continuing to heat them and allow them to cool down.
Heat acclimation is an important part of the health and safety process to protect employees when they are exposed to increased temperatures. While the most effective approach is to gradually increase the employees exposure to the conditions over a period of 7 to 14 days and ensure there is ample time to rest and respite, a smart safety solution can also be implemented to help monitor the employee through the process. To find out how this can help your organisation’s heat acclimatisation strategy and protect your employees in challenging conditions all year round, arrange a complimentary demo today. today.