Department of Kinesiology, California State University, Fresno.
Central California Sports Science Institute, California State University, Fresno.
J Athl Train. 2017 Nov;52(11):1056-1064. doi: 10.4085/1062-6050-52.11.15. Epub 2017 Nov 2.
The National Athletic Trainers' Association recommends using onsite wet-bulb globe temperature (WBGT) measurement to determine whether to modify or cancel physical activity. However, not all practitioners do so and instead they may rely on the National Weather Service (NWS) to monitor weather conditions.
To compare regional NWS WBGT estimates with local athletic-surface readings and compare WBGT measurements among various local athletic surfaces.
Observational study.
Athletic fields.
MAIN OUTCOME MEASURE(S): Measurements from 2 identical WBGT devices were averaged on 10 athletic surfaces within an NWS station reporting radius. Athletic surfaces consisted of red and black all-weather tracks (track), blue and black hard tennis courts (tennis), nylon-knit artificial green turf, green synthetic turfgrass, volleyball sand, softball clay, natural grass (grass), and a natural lake (water). Measurements (n = 143 data pairs) were taken over 18 days (May through September) between 1 pm and 4:30 pm in direct sunlight 1.2 m above ground. The starting location was counterbalanced across surfaces. The NWS weather data were entered into an algorithm to model NWS WBGT.
Black tennis, black track, red track, and volleyball sand WBGT recordings were greater than NWS estimates ( P ≤ .05). When all athletic-surface measurements were combined, NWS (26.85°C ± 2.93°C) underestimated athletic-surface WBGT measurements (27.52°C ± 3.13°C; P < .001). The range of difference scores (-4.42°C to 6.14°C) and the absolute mean difference (1.71°C ± 1.32°C) were large. The difference between the onsite and NWS WBGT measurements resulted in misclassification of the heat-safety activity category 45% (65/143) of the time ([Formula: see text]= 3.857, P = .05). The WBGT of water was 1.4°C to 2.7°C lower than that of all other athletic surfaces ( P = .04). We observed no other differences among athletic surfaces but noted large WBGT measurement variability among athletic playing surfaces.
Clinicians should use an onsite WBGT device to determine environmental conditions and the need for modification of athletic events, especially as environmental conditions worsen. Given the large WBGT variability among athletic surfaces, WBGT measurements should be obtained from each athletic surface.
美国国家运动训练员协会建议使用现场湿球黑球温度（WBGT）测量来确定是否需要修改或取消体育活动。然而，并非所有从业者都这样做，而是可能依赖于国家气象局（NWS）来监测天气状况。
比较区域 NWS WBGT 估计值与当地运动表面读数，并比较各种当地运动表面的 WBGT 测量值。
观察性研究。
运动场地。
在 NWS 报告半径内的 10 个运动表面上，对 2 个相同的 WBGT 设备的测量值进行平均。运动表面包括红色和黑色全天候赛道（赛道）、蓝色和黑色硬网球场地（网球）、尼龙针织人造绿草坪、绿色合成草皮、排球沙、垒球粘土、天然草皮（草皮）和天然湖泊（水）。在下午 1 点至 4 点 30 分之间，在直接阳光下，距离地面 1.2 米处，对 18 天（5 月至 9 月）内的 143 对数据进行了测量。起始位置在表面之间平衡。将 NWS 天气数据输入到算法中以模拟 NWS WBGT。
黑色网球、黑色赛道、红色赛道和排球沙的 WBGT 记录高于 NWS 估计值（P≤.05）。当组合所有运动表面的测量值时，NWS（26.85°C±2.93°C）低估了运动表面 WBGT 测量值（27.52°C±3.13°C；P<.001）。差值分数的范围（-4.42°C 至 6.14°C）和绝对平均差值（1.71°C±1.32°C）很大。现场和 NWS WBGT 测量之间的差异导致 45%（65/143）的时间活动分类错误（[Formula: see text]=3.857，P=.05）。水的 WBGT 比所有其他运动表面低 1.4°C 至 2.7°C（P=.04）。我们没有观察到运动表面之间的其他差异，但注意到运动场地的 WBGT 测量值存在很大的变异性。
临床医生应使用现场 WBGT 设备来确定环境条件和修改体育活动的必要性，尤其是在环境条件恶化的情况下。鉴于运动表面之间的 WBGT 差异很大，应从每个运动表面获取 WBGT 测量值。
