METHODOLOGY
In this research, ambient environmental conditions and heat strain indicators were measured on mine rescuers during mine rescue training exercises. The research described in this article was carried out between March 2002 and July 2003 Environmental monitoring was con-ducted
using conventional ventilation monitoring tools. Heat strain was mea sured using an ingestible temperature-sensing pill that measured core temperature continuously. In addition, a heart-rate monitoring chest strap was used to monitor heart rate continuously, which was a surrogate for
physical strain resulting from activity and heat. Both core temperature and heart rate data were transmitted to a remote recorder worn by a rescuer and time stamped Activities of the teams were also observed to determine the contribution of work rate to a person’s total heat load. The
focus of this research was to bridge the knowledge gap between labora tory-based studies under controlled, but assumed relevant, conditions and work rates encountered in underground mines
WBGT = 0.7 Tnwb +0.3 T globe
where Tnwb = natural wet bulb temperature
and T globe = globe temperature
(Goldstein and Kajdasz, 2000; Clayton and Clayton, 1991; Dinardi, 1988;
Plog, 1996; NIOSH, 1986)