Physiological responses to working with fire fighting equipment in the heat in relation to subjective fatigue.

Heart rate (HR), rectal temperature (Tre), blood pressure, temperature and relative humidity changes inside clothing were measured on 18 professional firemen (mean age 29.4 +/- 7.4 yr, VO2 max 41.4 + 8.8 ml kg-1 min-1) wearing fire fighter's uniforms (SU) or aluminized, fire resistant, impermeable clothing with self contained breathing apparatus (FE). The subjects exercised on a cycle ergometer with a work load of 1.5 W kg-1, at 39 +/- 1 degree C and at 70 +/- 5% relative humidity. They stopped exercising at a point of subjective fatigue and overheating which--according to their judgement--would cause them to stop working during real fire fighting. The working time until fatigue for subjects wearing FE was considerably lower than the corresponding value for SU. The HR and Tre values rose progressively throughout the exercise with no tendency to reach a plateau. In some cases the HR reached near maximal level. The Tre continued to rise even during 10 min of recovery and in many subjects exceeded 39 degrees C. These data showed that despite spontaneous termination of exercise, the limit of tolerance was reached by most of the subjects.

[1]  Barnard Rj,et al.  Heart rate and ECG responses of fire fighters. , 1975 .

[2]  Lemon Pw,et al.  The human energy cost of fire fighting , 1977 .

[3]  H. W. Duncan,et al.  Physiological responses of men working in fire fighting equipment in the heat. , 1979 .

[4]  V Louhevaara,et al.  Maximal working times with a self-contained breathing apparatus. , 1986, Ergonomics.

[5]  A. P. Hollander,et al.  Influence of heavy weight carrying on the cardiorespiratory system during exercise , 2004, European Journal of Applied Physiology and Occupational Physiology.

[6]  A Kilbom,et al.  Physical work capacity of firemen. With special reference to demands during fire fighting. , 1980, Scandinavian journal of work, environment & health.

[7]  G R Brisson,et al.  Body temperatures in relation to heart rate for workers wearing impermeable clothing in a hot environment. , 1978, American Industrial Hygiene Association journal.

[8]  V. Candas,et al.  Heart rate and spontaneous work-rest cycles during exposure to heat. , 1983, Ergonomics.

[9]  C O Dotson,et al.  Relationship between simulated fire fighting tasks and physical performance measures. , 1982, Medicine and science in sports and exercise.

[10]  R. Shephard.  World standards of cardiorespiratory performance. , 1966, Archives of environmental health.

[11]  E Kamon,et al.  Heart rate and rectal temperature relationships during work in hot humid environments. , 1971, Journal of applied physiology.

[12]  V Louhevaara,et al.  Effects of an SCBA on breathing pattern, gas exchange, and heart rate during exercise. , 1985, Journal of occupational medicine. : official publication of the Industrial Medical Association.

[13]  C H Wyndham,et al.  Assessing the Heat Stress and Establishing the Limits for Work in a Hot Mine , 1967, British journal of industrial medicine.

[14]  Per-Olof Åstrand,et al.  Experimental studies of physical working capacity in relation to sex and age , 1952 .

[15]  G. Ström,et al.  The Influence of Anoxia on Lactate Utilization in Man after Prolonged Muscnlar Work , 1949 .

[16]  J E Manning,et al.  Heart rates in fire fighters using light and heavy breathing equipment: similar near-maximal exertion in response to multiple work load conditions. , 1983, Journal of occupational medicine. : official publication of the Industrial Medical Association.

[17]  Cady Ld,et al.  Energy costs of simulated stair climbing as a job-related task in fire fighting. , 1986 .

[18]  Ethan R. Nadel,et al.  Problems with temperature regulation during exercise , 1977 .