title: Heat acclimatization by a method utilizing microclimate cooling.
abstract: A new approach to heat acclimatization has been shown to be feasible during laboratory experimentation. Wearing microclimate suits containing dry ice as the coolant, three groups of men were subjected to a moderate work rate in three different environments for 4 h/d for 8 d. Physiological responses on a subsequent heat tolerance test indicate that the group subjected to an environment of 32.0 degrees C W. B. and 33.5 degrees C D.B. were fully heat acclimatized. The 33/35 degrees C group were also well-acclimatized but developed dangerously high body temperatures during the first 2 d. Only partial acclimatization was achieved by the 31/33 degrees C group. The reason why the men acquire heat acclimatization while wearing the microclimate suits in a hot environment is probably that microclimate cooling does not prevent body temperature from rising--it only prevents it from rising excessively. It should be remembered that only one-third of the body is cooled while the rest shows the normal sweating response.
mesh_terms: D000064:Acclimatization; D001831:Body Temperature; D002980:Climate; D006339:Heart Rate; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008834:Microclimate; D008906:Mining; D009787:Occupational Medicine; D013019:South Africa; D013546:Sweating