After Dark: Assessing Hydration and Glucose Levels During Late Night Operations

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By A. Lynn Schofield


Provo Fire and Rescue has not evaluated the hydration or glucose levels on firefighters during late night operations. In addition, the department has not established the most effective method of providing fire ground rehabilitation. The result is arbitrary rehabilitation methods that may not meet the needs of firefighters operating late at night. This can result in decreased firefighter safety and performance.

The purpose of this Applied Research Project was to evaluate the physiological effects of late night operations on Provo firefighters. The project gathered data to answer these questions.

First, what are the hematological effects of strenuous activities during late night operations?

Second, do strenuous activities during late night operations create an increased risk to Provo Firefighters due to falling glucose levels and increased blood viscosity?

Third, what rehabilitation method provides the best short term and long term glucose and hydration replenishment in a firefighting scenario? And last, does rehabilitation improve firefighter efficiency and safety?

A process for evaluating the effects of late night operations was defined and collaborative partners were identified. An evaluation method using surveys, laboratory blood testing, analysis of vital signs, and other physiological indicators was set forth and a convenience sample of firefighters was obtained. In addition, additional research was completed on firefighter rehabilitation including the design of the rehabilitation regimens by a registered dietician.

With the testing parameters defined, the convenience sample of 13 firefighters from Provo Fire & Rescue, and Orem Fire Department, participated in testing sessions at 0200 and 0400 hours.

The raw data was recorded, analyzed, and converted to a usable form. The data suggests that physical activity, in personal protective equipment, caused physiological changes in the test subjects including weight loss, dehydration, increasing temperature, and shifts in blood chemistry. The data also suggests that a balanced diet, consisting of more complex carbohydrates and proteins provided a more stable nutritional platform for medium and long term firefighter rehabilitation.

The author recommends further study in both the physiological effects of firefighting activities and firefighter rehabilitation. The author further recommends a conscious shift in the role of rehab on the fire ground, identifying fluid replacement and nutritional supplements as a life safety issue.