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With severe weather conditions becoming more frequent and putting prolonged stress on first responders and workers alike, the topic of heat stress prevention is a growing concern. Just over the last two years, the number of reported wildfires in the US exceeded 41,000, with more to be expected during heatwaves like the recent one seen in the midwest. Wildland firefighters put their lives on the line every time they go out to the line of duty and these dangers are not preventable. However, learning to equip the proper FR gear that not only protects but also prevents heat exhaustion is a course of preventative action that can be taken to ensure more safety.


The first step to heat stress prevention is understanding the unique work environment and the standards that surround it. For example, the Wildland Firefighter Personal Protective Equipment Selection Guide from the Department of Homeland Security states that “Most domestic departments now use NFPA 1977 certification as a basis for selecting their WLFF PPE”. With this in mind, wildland firefighters are usually pictured wearing a bright yellow brush shirt that is NFPA 1977 certified. Although, what is worn underneath the brush shirt is oftentimes ignored.

1. Adding extra protection and airflow to the base layer

As an example and in many cases, wildland firefighters may simply wear a cotton shirt underneath their FR gear. If this is the case, the base layer will lack comfort as well as proper heat-resistant properties that are crucial to heat stress prevention during the summer season.


Albeit, FR t-shirts are thicker than normal fabric or cotton and thus can sometimes be more difficult to layer with. And if designed without the proper materials that allow for airflow, these shirts can be hard to layer with long sleeve brush shirts with the proper NFPA 1977 certification. However, it is not impossible to find a lightweight FR t-shirt option that is designed to have moisture control and breathable fabric properties.

Additionally, adding in this extra FR base layer not only increases overall protection, but it helps add airflow and moisture-wicking to your outfit which ultimately keeps your core body temperature cooler when you need to layer with a long sleeve.

2. Protecting from sunburn and covering sensitive neck/head areas

Another, if not one of the most important factors to heat stress prevention in the workplace is avoiding harmful UV rays from the sun. Sunburns are much more than simply getting a bit red from being out in the sun too long, but rather your skin’s defense mechanism to prevent damage to the deeper layers where the rays can affect or even damage to nerves and cells.


A bad sunburn can also affect the perceived body temperature, as there is increased blood flow to the affected areas which can cause mild to extreme discomfort. A severe sunburn can also lead to “sun poisoning” which will greatly affect one’s ability to function for the day and leaving them ill. Wearing breathable neck gaiters, bandanas, a do-rag, or a hybrid accessory that can be used as all of these will greatly reduce exposure to the sun. Additionally, if the accessory has heat-resistant properties, this will also help reduce core body temperature much like that of a cooling base layer.

3. hydrate - always have plenty of fluids available

This comes as a bit of an obvious statement - drink plenty of fluids. However, the importance of staying hydrated to outlast long shifts in the summer heat can never be stressed enough. There is an old adage that states eight 8oz glasses of water are needed per day, however, the origin of this is truly unknown. While this may come as no surprise, staying hydration is, if not the most important factor in heat stress prevention. In fact, the National Wildfire Coordinating Group (NWCG) found through its studies that wildland firefighters should drink 1 quart of fluid for each hour of work.

For example, hotshots and smokejumpers perform an extreme and physically demanding service. They work in smokey, and heated conditions which can result in dehydration at a much faster rate than normal. A tough job like this requires quick and easy access to water, ideally stored on or within a wildland pack.


Hydration packs provide the exact ease-of-access and high fluid quantity that outdoor workers, particularly wildland firefighters need. They hold enough water for the entire day (recommended up to 3 Liters) and can be secured to the back of a fire pack or stored within a personal backpack for ease of access.


Surely, there are more than 3 options for staying cool while on the job in the summer season. For example, some firefighters may opt for a light-colored long-sleeve FR t-shirt as their base layer which still retains the same heat-resistant qualities as a short sleeve. It truly comes down to on-the-job protective requirements and layering that with what feels best on the individual. Additionally, more information about protecting workers from heat stress can be found on this OSHA (Occupational Safety & Health Administration) informational card.