未习服男子干热暴露时的热调节反应

Thermoregulatory responses of non-acclimatized males during dry-heat exposure

１２名未习服健康男子，暴露于干热环境（Ｔｄ４２℃、Ｔｗ２３．５℃、Ｔｇ４６．５℃、ＲＨ１７％、ＷＢＧＴ３０℃、Ｖ０．１４～０．８０ｍ／ｓ）２．５ｈ，于受热１５和１２０ｍｉｎ时分别以功率１００Ｗ踏车５ｍｉｎ。结果呈现明显的热应激反应，Ｔｒ、Ｔｔ、Ｔｓ、Ｔｂ和ＨＲ增高非常显著（Ｐ＜０．０１）。Ｔｂ３７．１９℃，接近热负荷限度范围；最高Ｔｒ达到３８．８５℃，ＨＲ达１３６ｂ／ｍｉｎ，超过静止热负荷限度；ＳＶ仅０．２９３ｋｇ／ｈ，ＰＳＩ１．５，ＢＨＳＩ１２４ｋＪ／ｍ￣２，都低于耐受限度。但视反应时明显延长（Ｐ＜０．０５），握力降低３～５％。提示这样的干热应激对人体的热调节反应以及精神、体力和工作效率产生了一定的影响。

Twelve non-acclimatized healthy males were exposed to dry-heat environment at Td 42℃,Tw23. 5℃, Tg 46.5℃,RH17%, WBGT 30℃ and V 0. 14～0. 80m/s for 2. 5h; meanwhile, the subjects wereasked to tread on a bicycle ergometer for 5min with the power of 100w after heat exposure for 15min and120min separately. The results showed that responses to heat stress were obvious,and Tr,Tt,Ts,Tband HR increased significantly (P<0. 01).Tb was 37.19℃,approaching the limit of heat load.Tr of indi-vidual subject reached 38. 85℃,and the highest HR was 136b/min, and all exceeded the limit of heat loadin static state. SV was only 0.293kg/h, PSI 1.5, BHSI 124kJ/m￣2, all these indices were below the tolera-ble limit. But the visual reaction time was prolonged markedly(P<0.05),and grip decreased by 3～5%.It is suggested that such dry-heat stress has some influence on thermoregulatory response,and mental andphysical work efficiency.