Fire Fighting in Canada

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WellBeing: August 2016

Electrolyte deficiencies and dehydration are the most common preventable occupational hazards faced by firefighters. Firefighters, similar to high-level athletes, lose water rapidly during physical exertion. Water is the carrier of electrolytes, so dehydration leads to electrolyte depletion. Almost all firefighters have experienced an intense fire with searing, radiant heat, hours of physical activity in heavy bunker gear and quick changes in core body temperatures. The body depends on sweat to cool itself, so an extreme fire situation can quickly empty its water reserve.

There are a number of risk factors that affect depletion of water and minerals in a firefighter. Firefighters, wearing layers of non-breathable clothing to protect themselves, often deal with high temperatures inside a structure or outside on a hot summer day. Extreme sweating in these conditions depletes the body of all its water and good minerals.

Research conducted by the University of Cumbria in England, in collaboration with Cumbria Fire and Rescue Service, highlights how vital proper hydration is to a firefighter’s performance. The study identified that a high percentage of firefighters arrived to a training exercise or a real fire incident already significantly or severely dehydrated.

Electrolytes are minerals that are essential for the body to function. When water with electrolytes is consumed, the minerals are dissolved in the water and they enter the blood system. These minerals have ionic electrical charges that drive the function of every cell in the body. So imagine the importance minerals such as potassium, sodium, calcium and magnesium play in holding water in the body, making your cardiovascular system function and allowing energy production in muscle, brain and vital organs. Water and electrolytes are critical for peak performance, but are by far the most important health issue often overlooked. Dehydration, in extreme cases, can cause death.

 Potassium is probably the most important mineral in the body. Potassium helps maintain electrical activity in the brain and the heart. Potassium deficiency, for firefighters in extreme occupational situations, can be life threatening.  

The second most important and the second most abundant mineral in the body is phosphorus. Phosphorus is used for protein, fat and carbohydrate synthesis in the body; these key nutrients are integrated into DNA and cellular membranes. For firefighters, this mineral is mostly used in recovery after intense firefighting activity.

Sodium is known to regulate the level of water in the body. The more water you drink, the more sodium will be removed from your body via the kidneys. Sodium is used in transmitting important but subtle information from cell to cell in the body. Finding a good balance between sodium and water intake is critical.

Magnesium is responsible for more than 400 biochemical interactions in the body; about half the magnesium is found in critical organs such as the heart, nerves, muscles and the immune system. When firefighters experience muscle cramping during or after an intense fire, they should reach for large dosages of magnesium to reverse the effects. Depleted magnesium stores in the body prevent the muscles from physiologically performing. If a muscle does not slide properly, sudden movements can damage the tissue. A muscle pull is the most common fire-scene injury for firefighters.

There are many signs associated with electrolyte and water deficiency and imbalance. In the rush of life and especially fire fighting, we often overlook the simple act of rehydration. Examples of symptoms associated with water and electrolyte deficiencies include muscle spasms, restlessness, insomnia, dizziness, headaches, fever, heart activity, heart palpitations and blood pressure issues. If ignored and not treated, these symptoms become chronic and sometimes life threatening.

Finding electrolytes and water in whole, complete foods is a great way to increase minerals in the body. Vegetables are an excellent source of electrolytes, especially when combined in a soup. Consider adding kale, artichoke, spinach, parsley and Swiss chard into your diet. Another way to boost mineral intake is to use salts that contain more minerals, such as Himalayan, Celtic or sea salt. Fruits can also be a great source of minerals and water, including bananas, coconuts and avocados.

As a firefighter, make sure you are properly hydrated and balanced with electrolytes to maintain an optimum performing body.

Elias Markou is in private practice in Mississauga, Ont., and is the chief medical officer for the Halton Hills Fire Department. Markou was a volunteer firefighter for six years and is now a firefighter health expert and blogger who is regularly featured on television and radio and in print. Contact him at

July 14, 2016 
By Elias Markou

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