Tikuisis Peter, Keefe Allan A, Keillor Jocelyn, Grant Stuart, Johnson Richard F
Defence Research and Development Canada-Toronto, Human Protection and Performance, Toronto, ON, Canada.
Aviat Space Environ Med. 2002 Dec;73(12):1176-83.
Marksmanship has been reported to deteriorate during exposure to heat or cold, yet the effect of the resultant thermal strain in isolation of the inflicting thermal stress is not entirely clear. In most studies, the debilitating effects on marksmanship are confounded by an evolving thermal strain (in terms of body heat storage/debt).
Thermal strain (hot and cold) should degrade marksmanship, more with moving targets than with conventional pop-up targets that are deemed less challenging.
The 12 rifle-trained military reservists (7 men and 5 women) were tested on their marksmanship skills using a small arms simulator. Subjects conducted three trials in an environmentally controlled chamber, 1 wk apart in a counter-balanced order. Trial conditions were neutral (N; 22 degrees C), hot (H; 35 degrees C), and cold (C; 5 degrees C), and all were preceded with an immersion in water to chest level to establish thermal strain (for H and C) or to maintain thermal neutrality prior to shooting. Subjects fired a C7 rifle at various targets during sixteen 5-min engagements over 2 h. Targets were presented either as moving in an urban setting or as pop-ups in a lane setting. Body temperatures, heart rate, saliva cortisol concentration, subjective ratings, and measures of marksmanship accuracy and precision were recorded and analyzed using a repeated measures design.
Mean +/- SD of the rectal temperature during the shooting were 36.9 +/- 0.2 degrees C, 37.7 +/- 0.3 degrees C, and 36.8 +/- 0.6 degrees C for N, H, and C, respectively (H > N, C). Corresponding hand temperatures were 31.5 +/- 1.2 degrees C, 35.2 +/- 0.7 degrees C, and 19.4 +/- 3.0 degrees C (H > N > C). These body temperatures were consistent with the subjective indices of heat illness, cold discomfort, and muscle discomfort. Cortisol concentration and perceived exertion were higher during H. Surprisingly, thermal strain did not degrade marksmanship. Instead, some aspects of precision (horizontal displacement) and accuracy (shooting error) were poorer during N compared with H and C.
Deep body temperatures not higher than approximately 37.9 degrees C and not less than 36.4 degrees C (accompanied by hand temperatures of not less than 19 degrees C) do not negatively affect rifle marksmanship performance, even if significant respective sensations of heat and cold are present.
据报道，在受热或受冷时射击精度会下降，但仅由热应激导致的热应变对射击精度的影响尚不完全清楚。在大多数研究中，射击精度下降的不利影响与不断变化的热应变（就身体热量储存/亏欠而言）相互混淆。
热应变（热和冷）会降低射击精度，对移动目标的影响大于对被认为挑战性较小的传统弹出式目标的影响。
12名接受过步枪训练的军事预备役人员（7名男性和5名女性）使用小型武器模拟器测试他们的射击技能。受试者在环境可控的舱室内进行三次试验，试验间隔为1周，采用平衡顺序。试验条件为中性（N；22摄氏度）、热（H；35摄氏度）和冷（C；5摄氏度），在射击前，所有受试者均将胸部浸入水中以建立热应变（对于H和C）或保持热中性。受试者在2小时内进行16次5分钟的射击，用C7步枪射击各种目标。目标呈现为在城市环境中移动或在巷道环境中弹出。记录体温、心率、唾液皮质醇浓度、主观评分以及射击精度和精准度的测量值，并使用重复测量设计进行分析。
射击期间直肠温度的平均值±标准差，N组为36.9±0.2摄氏度，H组为37.7±0.3摄氏度，C组为36.8±0.6摄氏度（H＞N，C）。相应的手部温度分别为31.5±1.2摄氏度、35.2±0.7摄氏度和19.4±3.0摄氏度（H＞N＞C）。这些体温与中暑、寒冷不适和肌肉不适的主观指标一致。H组期间皮质醇浓度和感知运动用力程度较高。令人惊讶的是，热应变并未降低射击精度。相反，与H组和C组相比，N组在精度（水平位移）和准确性（射击误差）的某些方面较差。
即使存在明显的热感和冷感，深部体温不高于约37.9摄氏度且不低于36.4摄氏度（同时手部温度不低于19摄氏度）不会对步枪射击性能产生负面影响。
