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Cool Under Pressure: Reducing Heat Stress in the Workplace with Helmet Technology

• Sep 10, 2024

Additionally, human skin does not directly sense moisture; instead, it perceives moisture through a combination of temperature and tactile cues. This leads to a strong interaction between temperature and humidity perception.

OSHA now uses the Wet Bulb Globe Temperature (WBGT) as a more comprehensive measure to gauge heat risk levels, taking into account not just temperature and humidity, but also wind speed, sun exposure and other environmental factors. This broader pool of data provides a more accurate representation of the potential heat stress risks in a given environment, helping to protect workers from heat-related illnesses.

In the context of the microclimate inside workers’ helmets, the Heat Index is a useful metric for evaluating the overall heat experienced by the wearer. However, for assessing heat risk in broader workplace environments, the Wet Bulb Globe Temperature represents the new, more comprehensive standard. Both methods of measuring effective temperature have their respective roles in evaluating heat factors in the workplace. It is crucial for health and safety experts to understand the differences between the two to effectively manage heat stress.

Test Setup

Recognizing the need for better evaluation methods, it was necessary to develop a test protocol to assess the thermal comfort of industrial helmets. This method involved using a head form that simulates human sweating. The head form, equipped with a semipermeable membrane that only allows water vapor to pass, mimics human thermoregulation in a controlled setting. A water basin heated to 37 degrees C or 98.6 degrees F was used to replicate skin temperature and the build-up of humidity.

Helmets were tested at room temperature, with the head form set at 37 degrees C or 98.6 degrees F. The humidity and temperature were monitored for over an hour. Sensors placed around the head form collected data on temperature, relative humidity and absolute humidity, which were then used to calculate the heat index (HI).

This comprehensive approach ensures that the evaluation reflects real-world conditions as closely as possible. By simulating actual workplace environments, this testing method provides a more accurate assessment of how their helmets perform under various thermal conditions. This level of detailed analysis is crucial in developing protective gear that not only meets but exceeds current safety standards, ensuring that workers are protected in increasingly extreme environmental conditions.

Results

The test results showed a significant reduction in heat stress for helmets with full integration compared to traditional foam-based helmets. These safety helmets demonstrated a reduction in head index of up to 4.5 degrees C or 8 degrees F.

This structure, which is 95 percent air, allows heat and humidity to escape, aiding in thermoregulation and providing greater comfort during prolonged use. This feature reduces the risk of heat-related injuries and fatalities by improving airflow and preventing sweat accumulation. Importantly, this can also help prevent the temptation to remove PPE in hot conditions, which can lead to injuries or fatalities. It is crucial for employers to understand how their choice of PPE, particularly helmets, impacts their workers’ health. Investing in advanced protective solutions like those incorporating this technology is vital in addressing the increasing global temperatures and ensuring the safety and well-being of workers.

As we continue to face the challenges of a warming climate, the importance of heat stress mitigation in the workplace cannot be overstated. Employers must prioritize not only the physical protection of their workers but also their thermal comfort. By adopting advanced PPE solutions that incorporate innovative technologies, industries can better safeguard their workforce against the growing threat of heat-related illnesses and enhance overall safety and productivity.

This article originally appeared in the September 2024 issue of Occupational Health & Safety.