Ferretti G, Veicsteinas A, Rennie D W
Department of Physiology, Centre Médical Universitaire, Geneva, Switzerland.
J Appl Physiol (1985). 1988 Mar;64(3):1239-48. doi: 10.1152/jappl.1988.64.3.1239.
Trunk (HT), limb (HL), and whole-body (HDIR = HT + HL + Hforehead) skin-to-water heat flows were measured by heat flow transducers on nine men immersed head out in water at critical temperature (TCW = 30 +/- 2 degrees C) and below [overall water temperature (TW) range = 22-32 degrees C] after up to 3 h at rest and exercise. Body heat flow was also determined indirectly (HM) from metabolic rate corrected for changes in heat stores. At rest at TCW [O2 uptake (VO2) = 0.33 +/- 0.07 l/min, n = 7], HT = 52.3 +/- 14.2 (SD) W, HL = 56.4 +/- 14.6 W, HDIR = 120 +/- 27 W, and HM = 111 +/- 29 W (significantly different from HDIR). TW markedly affected HDIR but only slightly affected HM (n = 22 experiments at TW different from TCW plus 7 experiments at TCW). During light exercise (3 MET) at TCW (VO2 = 1.06 +/- 0.26 l/min, n = 9), HT = 122 +/- 43 W, HL = 130 +/- 27 W, HDIR = 285 +/- 69 W, and HM = 260 +/- 60 W. During severe exercise (7 MET) at TCW (VO2 = 2.27 +/- 0.50 l/min, n = 4), HT = 226 +/- 100 W, HL = 262 +/- 61 W, HDIR = 517 +/- 148 W, and HM = 496 +/- 98 W. Lowering TW at 7-MET exercise (n = 9, plus 4 at TCW) had no effect on HDIR and HM. In conclusion, resting HL and HT are equal. At TW less than TCW at rest, HDIR greater than HM, showing that unexpectedly the shell was still cooling. During exercise, HL increases more than HT but less than expected from the heat production of the working limbs. Therefore some heat produced by the limbs is probably transported by blood to the trunk. During heavy exercise, HDIR is constant at all considered TW; apparently it is regulated by some thermally dependent mechanism, such as a progressive cutaneous vasodilation occurring as TW increases.
通过热流传感器测量了9名男性的躯干（HT）、肢体（HL）和全身（HDIR = HT + HL + 额头热量）皮肤与水之间的热流。这些男性头部露出浸泡在临界温度（TCW = 30 ± 2℃）及以下的水中[总体水温（TW）范围 = 22 - 32℃]，此前他们分别进行了长达3小时的静息和运动。还通过对热储存变化进行校正后的代谢率间接测定了身体热流（HM）。在TCW静息状态下[摄氧量（VO2） = 0.33 ± 0.07升/分钟，n = 7]，HT = 52.3 ± 14.2（标准差）瓦，HL = 56.4 ± 14.6瓦，HDIR = 120 ± 27瓦，HM = 111 ± 29瓦（与HDIR有显著差异）。TW显著影响HDIR，但对HM影响较小（在与TCW不同的TW下进行了22次实验，在TCW下进行了7次实验）。在TCW进行轻度运动（3代谢当量）时（VO2 = 1.06 ± 0.26升/分钟，n = 9），HT = 122 ± 43瓦，HL = 130 ± 27瓦，HDIR = 285 ± 69瓦，HM = 260 ± 60瓦。在TCW进行剧烈运动（7代谢当量）时（VO2 = 2.27 ± 0.50升/分钟，n = 4），HT = 226 ± 100瓦，HL = 262 ± 61瓦，HDIR = 517 ± 148瓦，HM = 496 ± 98瓦。在7代谢当量运动时降低TW（n = 9，在TCW时为4）对HDIR和HM没有影响。总之，静息时HL和HT相等。在静息状态下TW低于TCW时，HDIR大于HM，表明出人意料的是体表仍在散热。运动期间，HL的增加幅度大于HT，但小于工作肢体产热预期的增加幅度。因此，肢体产生的一些热量可能通过血液输送到躯干。在剧烈运动期间，在所有考虑的TW下HDIR保持恒定；显然它受某种热依赖机制调节，例如随着TW升高而发生的渐进性皮肤血管舒张。
