Comparison of active cooling devices with passive cooling for rehabilitation of firefighters performing exercise in thermal protective clothing: a report from the Fireground Rehab Evaluation (FIRE) trial.
BACKGROUND
Thermal protective clothing (TPC) worn by firefighters provides considerable protection from the external environment during structural fire suppression. However, TPC is associated with physiologic derangements that may have adverse cardiovascular consequences. These derangements should be treated during on-scene rehabilitation periods.


OBJECTIVE
To examine heart rate and core temperature responses during the application of four active cooling devices, currently being marketed to the fire service for on-scene rehabilitation, and compare them with passive cooling in a moderate temperature (approximately 24 degrees C) and with an infusion of cold (4 degrees C) saline.


METHODS
Subjects exercised while they were wearing TPC in a heated room. Following an initial exercise period (bout 1), the subjects exited the room, removed the TPC, and for 20 minutes cooled passively at room temperature, received an infusion of cold normal saline, or were cooled by one of four devices (fan, forearm immersion in water, hand cooling, or water-perfused cooling vest). After cooling, the subjects donned the TPC and entered the heated room for another 50-minute exercise period (bout 2).


RESULTS
The subjects were not able to fully recover core temperature during a 20-minute rehabilitation period when provided rehydration and the opportunity to completely remove the TPC. Exercise durations were shorter during bout 2 when compared with bout 1 but did not differ by cooling intervention. The overall magnitudes and rates of cooling and heart rate recovery did not differ by intervention.


CONCLUSIONS
No clear advantage was identified when active cooling devices and cold intravenous saline were compared with passive cooling in a moderate temperature after treadmill exercise in TPC.
Hostler
David
D
Department of Emergency Medicine, Emergency Responder Human Performance Laboratory, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA. hostlerdp@upmc.edu
Reis
Steven E
SE
Bednez
James C
JC
Kerin
Sarah
S
Suyama
Joe
J
D000328:Adult; D001831:Body Temperature / Q000502:physiology*; D017679:Cryotherapy / Q000295:instrumentation*; D004651:Employment; D015444:Exercise / Q000502:physiology*; D005260:Female; D005390:Fires; D006359:Heat Exhaustion / Q000503:physiopathology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D011481:Protective Clothing / Q000009:adverse effects*; D013647:Task Performance and Analysis; D055815:Young Adult
Med Sci Sports Exerc. 2008 Mar;40(3):523-8
18379216
Ergonomics. 2004 Aug 15;47(10):1073-86
15370864
Aviat Space Environ Med. 2007 Jun;78(6):561-7
17571655
Ann Emerg Med. 2008 Feb;51(2):153-9
18045737
Eur J Appl Physiol Occup Physiol. 1995;70(4):322-8
7649143
Med Sci Sports Exerc. 1998 Mar;30(3):468-72
9526896
J Athl Train. 2009 Mar-Apr;44(2):124-35
19295956
Br J Nutr. 1978 Nov;40(3):497-504
718832
J Occup Environ Med. 1999 Dec;41(12):1104-15
10609231
J Occup Environ Hyg. 2004 Apr;1(4):199-212
15204859
N Engl J Med. 2007 Mar 22;356(12):1207-15
17377158
Ergonomics. 2004 Jan 15;47(1):75-90
14660219
Eur J Appl Physiol. 2009 Nov;107(4):385-96
19649650
Ann Occup Hyg. 1999 Jul;43(5):289-96
10481628
Can J Appl Physiol. 1999 Aug;24(4):349-61
10470451
Aviat Space Environ Med. 1994 Aug;65(8):757-63
7980339
Ergonomics. 1999 Feb;42(2):299-313
10024849
J Occup Environ Med. 1999 Jun;41(6):469-79
10390698
Eur J Appl Physiol. 2009 Mar;105(4):607-13
19037655
J Occup Environ Hyg. 2009 May;6(5):283-8
19242856
Med Sci Sports Exerc. 1990 Oct;22(5):704-12
2233211
J Occup Environ Hyg. 2004 Aug;1(8):521-31
15238305