Staying hydrated is vital in the fire service

When I was a young firefighter in the early 1980s, my department did not carry any kind of drinking water supply on the rigs. Individuals could stash a water bottle in their seats, but more often than not, we would be out for hours on a searing summer day with no access to fluids in any form.

That situation changed over the years – every engine and truck began carrying a large cooler jug full of water, and the battalion chief always had a case of sports drinks in his truck. But it was still extremely difficult to stay adequately hydrated at work, and we all suffered the consequences.

How dehydration affects the body

Even mild dehydration results in significant negative physical outcomes: headache, exhaustion, rapid pulse, irritability. Mild dehydration occurs when a person is just 1.5 percent dehydrated – a condition that does not even trigger the thirst response in most people.

Many people will become 1.5 percent dehydrated after just an hour of moderate hiking with no fluid intake. For someone who is running at midrange intensity, this condition can occur within half an hour.

Just imagine how quickly a firefighter working on an initial attack would reach the level of measurable dehydration.

The physical effects of dehydration are serious; if left untreated, they can lead to dizziness, fever, seizures, coma or even death. But researchers are now finding that even mild dehydration has negative cognitive effects as well.

A recent study conducted by Yale University showed that participants who were just 1 percent dehydrated had a 12 percent increase in errors when performing tasks that required cognitive flexibility. This effect was reversible when hydration was returned to normal.

In addition, dehydration is known to worsen mood and attitude, contribute to confusion and poor decision making, and negatively affect memory and judgment.

In other words, you really don’t want your incident commander and firefighters on a critical scene to be even slightly dehydrated.

And yet, dehydration is common, even among the general public, and much more so among people who are performing at physically high levels under adverse conditions. It is often difficult for people to know that they are dehydrated, since the negative effects usually kick in before thirst is noticed. In dry climates, dehydration can be more dangerous, since sweat often evaporates before it is felt, and even breathing can lead to loss of body fluid. Breathing off an SCBA also leads to loss of fluids since the compressed air is so dry.

How firefighters can proactively fight dehydration

What can fire departments do to increase the chances that all members are adequately hydrated? The first step is awareness that dehydration is always a risk, and that firefighters must be proactive in preventing it.

Obviously, firefighters should increase their intake of fluids, though not just any fluids. Although coffee can be somewhat hydrating for people who are accustomed to drinking it regularly, caffeine can also have a diuretic effect that reduces any potential benefit. Plain water is the best hydration solution, but must be ingested continuously throughout the day, not simply all at once. Fruits and vegetables also count toward daily fluid intake but watch out for sugary or carbonated beverages. Electrolyte and enhanced sports drinks can be useful in moderation but should never be entirely substituted for water when rehydrating.

Every rig should carry its own supply of cool water at all times, and individual firefighters might want to keep a personal water bottle with them as well. Since it is not possible to rehydrate when actively fighting fire, and this is when the most body fluids are likely to be lost, rotating firefighters regularly through the rehab sector is critical, whether they think they need a break or not. As soon as they take off their masks, hand them a bottle of water and don’t let them leave until they have finished it.

As a scene commander, watch for signs of dehydration among your crews. Are people slowing down, sweating profusely, stumbling or making small mistakes? Dehydration could be a contributing factor. Do not wait to intervene, since the effects of dehydration dramatically worsen over time.

And those in charge must remember to take care of themselves as well. As an incident commander, it may not seem like you are doing the same heavy work as the inside fire crews, and you may not think you have the same physical needs. This would be a false conclusion. Keep everyone on the scene as adequately hydrated as possible. You can’t afford to allow even a slight decrease in physical or cognitive function when the stakes are life and death.

This article was published on Aug. 22, 2018 and has been updated.