Effects of frequent use of air cooling system on children's heat tolerance.

1998 Fiscal Year Final Research Report Summary

• Project/Area Number: 09680064
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 家政学
• Research Institution: Kyushu Institute of Design
• Principal Investigator: TOSHIHARA Yutaka Kyushu Institute of Design, Faculty of Design, Professor, 芸術工学部, 教授 (50095907)
• Co-Investigator(Kenkyū-buntansha): OHNAKA Tadakatsu Fukuoka Women's University, Faculty of human Envionmental Sciences, Professor, 人間環境学部, 教授 (20112716)
• Project Period (FY): 1997 – 1998
• Keywords: Children / Rectal temperature / Activated sweat grant / Sweat rate, / Air cooling system, / Blood flow

Research Abstract

Kuno reported that the number of active sweat grants is decided by the ambient temperature of one's living environment for the first two years after birth. The purpose of this experiment is to investigate whether frequent use of an air cooling system in infancy affects children's heat tolerance or not. Twenty-nine children served as the subjects. Their ages were from 7 to 10 years old. The children were divided into two groups one was the group (Group C) who did not use an air cooling system in their infancy (n=7), the other (Group N) was the group who used an air cooling system frequently in summer (n=22). The subject stayed in a pre-room of 28ﾟC for more than 30 minutes. Thereafter they sat in a hot room of 30ﾟC with 70% rh for 60 minutes, and for the last 40 minutes their legs were immersed up to the knees in bath water of 42ﾟC.Rectal and 7 points skin temperatures, blood flow at forearm, local sweat rate at forearm and back, heart rate and blood pressure were measured during the experiments. Total sweat rate was determined by the measurements of body weight and the beginning and the end of the heat exposure. The number of heat activated sweat grants and Na^+ of sweat at back, forearm, chest and thigh were measured at the end of the heat exposure. These experiments were carried out in July and August. The increases in rectal temperature by feet immersion in Group C were significantly higher than those in Group N.Mean skin temperature, forearm skin temperature and forearm blood flow during the immersion in Group C were significantly higher than those in Group N.However, there were no significant differences in the number of heat activated grants and sweat rate between the groups.