Somboonwong Juraiporn, Sanguanrungsirikul Sompol, Pitayanon Chatchatchai
Department of Physiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
BMJ Open. 2012 Jul 7;2(4). doi: 10.1136/bmjopen-2011-000741. Print 2012.
This study aimed to determine thermoregulatory and cardiovascular responses as well as the occurrence of heat illness in children exercising outdoors in physical education class under hot and humid climate. Little information regarding this issue under real-life situation is available, especially in the Southeast Asia.
Analytical, prospective descriptive study.
A primary school in Bangkok, Thailand.
A total of 457 schoolboys (aged 5.5-12 years) were observed while exercising outdoors during their physical education classes throughout the academic year of 2009, including semester 1 (between July and September 2009) and semester 2 (between November 2009 and February 2010).
Primary outcome measure was tympanic temperature. Secondary outcome measures included blood pressure, heart rate, hydration status and the occurrence of heat-related illness.
Outdoor physical activity consisted of skill practice (duration 24.11±11.04 min, intensity <3 metabolic equivalent of tasks) and playing sports (duration 11.48±5.53 min, intensity 2.6-8.8 metabolic equivalent of tasks). After exercise, tympanic temperature increased by 0.66±0.41°C. There were 20 (4.4%) students whose ear temperature exceeded 38°C, 18 of whom did not consume water. The RR of increasing body temperature up to 38°C in overweight students was 2.1-fold higher than normal-weight students. The per cent change in mean arterial pressure and heart rate increased by 20.16±15.34% and 23.94±19.78%, respectively. Sweat and dehydration rates were 391.16±186.75 ml/h and 0.63±0.26%, respectively. No evidence of heat illness was found. Wet bulb globe temperatures of semesters 1 and 2 were 29.95±1.87°C and 28.32±2.39°C, respectively.
There is an increased risk for heat illness during outdoor activities in physical education class in primary school children, especially those who are overweight and have poor hydration status.
本研究旨在确定在炎热潮湿气候下，小学生在体育课室外锻炼时的体温调节和心血管反应以及中暑的发生情况。在现实生活中，尤其是在东南亚地区，关于这个问题的信息很少。
分析性前瞻性描述性研究。
泰国曼谷的一所小学。
在2009学年的体育课室外锻炼期间，共观察了457名男学生（年龄5.5 - 12岁），包括第1学期（2009年7月至9月）和第2学期（2009年11月至2010年2月）。
主要观察指标是鼓膜温度。次要观察指标包括血压、心率、水合状态和中暑的发生情况。
室外体育活动包括技能练习（持续时间24.11±11.04分钟，强度<3代谢当量任务）和进行体育运动（持续时间11.48±5.53分钟，强度2.6 - 8.8代谢当量任务）。运动后，鼓膜温度升高了0.66±0.41°C。有20名（4.4%）学生的耳温超过38°C，其中18名学生没有喝水。超重学生体温升高至38°C的相对风险是正常体重学生的2.1倍。平均动脉压和心率的百分比变化分别增加了20.16±15.34%和23.94±19.78%。出汗率和脱水率分别为391.16±186.75毫升/小时和0.63±0.26%。未发现中暑迹象。第1学期和第2学期的湿球黑球温度分别为29.95±1.87°C和28.32±2.39°C。
小学生在体育课室外活动期间中暑风险增加，尤其是那些超重且水合状态不佳的学生。
