JOURNAL ARTICLE

Physiological responses of medical team members to a simulated emergency in tropical field conditions

Matt B Brearley, Michael F Heaney, Ian N Norton
Prehospital and Disaster Medicine 2013, 28 (2): 139-44
23340114

INTRODUCTION: Responses to physical activity while wearing personal protective equipment in hot laboratory conditions are well documented. However less is known of medical professionals responding to an emergency in hot field conditions in standard attire. Therefore, the purpose of this study was to assess the physiological responses of medical responders to a simulated field emergency in tropical conditions.

METHODS: Ten subjects, all of whom were chronically heat-acclimatized health care workers, volunteered to participate in this investigation. Participants were the medical response team of a simulated field emergency conducted at the Northern Territory Emergency Services training grounds, Yarrawonga, NT, Australia. The exercise consisted of setting up a field hospital, transporting patients by stretcher to the hospital, triaging and treating the patients while dressed in standard medical response uniforms in field conditions (mean ambient temperature of 29.3°C and relative humidity of 50.3%, apparent temperature of 27.9°C) for a duration of 150 minutes. Gastrointestinal temperature was transmitted from an ingestible sensor and used as the index of core temperature. An integrated physiological monitoring device worn by each participant measured and logged heart rate, chest temperature and gastrointestinal temperature throughout the exercise. Hydration status was assessed by monitoring the change between pre- and post-exercise body mass and urine specific gravity (USG).

RESULTS: Mean core body temperature rose from 37.5°C at the commencement of the exercise to peak at 37.8°C after 75 minutes. The individual peak core body temperature was 38.5°C, with three subjects exceeding 38.0°C. Subjects sweated 0.54 L per hour and consumed 0.36 L of fluid per hour, resulting in overall dehydration of 0.7% of body mass at the cessation of exercise. Physiological strain index was indicative of little to low strain.

CONCLUSIONS: The combination of the unseasonably mild environmental conditions and moderate work rates resulted in minimal heat storage during the simulated exercise. As a result, low sweat rates manifested in minimal dehydration. When provided with access to fluids in mild environmental conditions, chronically heat-acclimatized medical responders can meet their hydration requirements through ad libitum fluid consumption. Whether such an observation is replicated under a harsher thermal load remains to be investigated.

Full Text Links

Find Full Text Links for this Article

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read
23340114
×

Save your favorite articles in one place with a free QxMD account.

×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"