The effects of fencing uniforms (U) on thermoregulatory responses were analyzed in both practical field investigation (PFI) and laboratory experiment (LE) . In PFI, six fencers (college-aged) performed regular fencing practice wearing U and wearing a short-sleeved shirt and pants (T) in summer. Rectal temperature (Tr), chest skin temperature (Tch), mask temperature (Tmk), heart rate (HR) and sweat rate (SR) were measured during fencing practice. In LE, seven male college-aged subjects performed three sessions of 20-min cycling at light intensity (250 W/m²) in a room temperature maintained at 28 WBGT (wet bulb globe temperature) . Esophageal temperature (Tes), mean skin temperature (Tsk), mean body temperature (Tb), HR, and SR were measured during exercise wearing U and in a semi-nude condition (N) . In both PFI and LE, increases in Tch, Tsk, Tb, Tes, Tr and SR were significantly (p<0.001) greater when wearing U than when wearing T and N. In PFI, the maximal value of Tr correlated significantly with the maximal values of Tch (r=0.513, p<0.001) and SR (r=0.635, p<0.001) during practice wearing U and T. In LE, positive correlations between Tsk and Tes (r=0.797, p<0.001), and between Tb and SR (r=0.658, p<0.02) were found at the end of exercise wearing U and N. In PFI, although the Tsk decreased within a few minutes of a decrease in Tmk, a significant relationship between the decrease in Tmk and Tsk or Tr was not observed during fencing practice. These results demonstrate that when wearing U, a higher skin temperature induces core temperature elevation, and higher skin and core temperatures are associated with increases in SR and HR during exercise in a hot environment. Thus, wearing light clothing during exercise, and taking off the fencing jacket and mask during rest periods would be recommended to reduce the heat stress during fencing practice in hot environments.

To clarify the effect of sports wear on exercise-heat stress, we analyzed quantitative differences in thermoregulatory responses among baseball uniforms (BB), soccer uniforms (SC), and swimming trunks (NU) during exercise in a hot environment. Eight male subjects performed three sessions of 20-min cycling at light intensity (250W/m²) wearing BB, SC and NU in a room maintained at 28°C (wet-bulb globe temperatures, WBGT) . Esophageal (Tes), mean skin (Tsk), and mean body temperatures (Tb), heart rate (HR), thermal sensation (TS), and total sweat loss (m_SW) were measured during the exercise. Increases in Tes, Tsk, Tb, HR, and TS during exercise were significantly (p<0, 05) higher, and m_SW, was significantly (p<0.001) greater for BB than SC and NU. The increase in Tes at the end of the exercise was 3.0 times higher for BB than NU ; and also 2.0 times higher for SU than NU. Under all conditions, the increase in Tes significantly correlated with Tsk (r=0.634, p<0, 001) and HR (r=0.854, p<0.001) ; m_SW also significantly correlated with Tb (r=0.683, p<0.001) at the end of the exercise. These findings suggest that quantitative differences regarding the increase in Tes among BB, SC and NU relate to Tsk elevation due to attenuation of heat dissipation depending on sports wear ; body temperature elevation also relates to the increase in HR and m_SW during light exercise in a hot environment.

To clarify the effects of varying skin temperature due to several types of clothing on temperature responses and heat-stress during exercise, we analyzed thermoregulatory responses while wearing various types of sportswear including soccer (SC), baseball (BB), and fencing uniforms (FU), and while wearing water-perfused suits (WS) and vests (WV) during exercise in a hot environment. We also compared these results with those obtained under a semi-nude condition (NU). Eight male subjects performed three 20-min cycling sessions at light intensity (250W/m²) in a room maintained at 28°C (wet-bulb globe temperature, WBGT). The experiment was performed under ten conditions, with six sets of clothing, WS and WV at 14°C (WS14, WV14), 20°C (WS20, WV20) and 26°C (WS26, WV26), and FU, SC, BB or NU. While wearing sport-swear, increases in esophageal (ΔTes), mean skin (Tsk), mean body (Tb) temperature, heart rate (HR), thermal sensation (TS) at the end of exercise, and total sweat loss (m_{sw, tot}) during exercise were significantly (p<0.01) higher in BB and FU than in NU. In comparison to WS or WV conditions, ΔTes was significantly (p<0.01) higher under WV conditions than under NU, while there was no significant difference in ΔTes between WS and NU. Tsk, Tb, HR, TS and m_{sw, tot} tended to be lower in WS14 and 20, and higher in WV26 than in NU. Under all conditions at the end of exercise, the ΔTes markedly increased when Tsk exceeded 34°C ; and ΔTes was significantly correlated with Tsk (r=0.861, p<0.01) for all conditions except WS14 and 20. For Tsk less than 34°C, however, ΔTes remained constant. ΔTes, Tsk, and Tb significantly correlated with HR (r=0.932, p<0.001), TS (r=0.888, p<0.001), and m_{sw, tot} (r=0.961, p<0.001), respectively. These results show that during light exercise under hot conditions, 1) in several types of clothing, a critical level of skin temperature causing core temperature elevation may exist, 2) cooling the skin temperature can alleviate heat-stress due to body temperature elevation, and 3) the semi-nude condition is the simplest method of alleviating core temperature elevation without using body cooling materials such as WS or WV.

The guidelines for the prevention of heat disorders during sports activities were established 13 years ago in Japan. Since then, various studies on preventive measures against heat disorders have been done, yielding new knowledge about its prevention. It has been reported that the incidence of heat disorders is high in children and the elderly, and heat acclimatization and clothing are the factors involved in this disorder. We proposed to lower the WBGT (wet-bulb globe temperature) limit for warning (discontinuation of hard exercise) from “28°C or more” to “25°C or more” (corresponding to an ambient temperature of 28°C) for non-acclimatized persons, children, the elderly, and persons wearing clothes covering the entire body. We also indicated that heat disorders can occur due to unpredictable causes, because the mechanism is very complicated.

Although it is very important in view of public health to understand the mosquito breeding sites and key reservoirs existing around residential areas, such information is lacking in temporary housing sites constructed after the serious tsunami strikes on 26 December 2004 in Sri Lanka. This study clarified the situation regarding mosquito breeding 14 months after the tsunami in Sri Lanka by surveying temporary housing and non-damaged village areas, and also by examining people‘s knowledge related to mosquito breeding sites and mosquito-borne diseases. The relative frequency of mosquito larvae in wastewater pools was significantly higher in temporary housing than in village areas. The prevalence of storage containers at temporary housing and village areas was not significantly different. It was found that wastewater pools in temporary housing sites were the main breeding site of Culex quinquefasciatus Say, Cx. tritaeniorhynchus Giles, and Aedes albopictus Skuse whereas storage containers in village areas were the main breeding site of Cx. quinquefasciatus and Ae. albopictus. No mosquitoes bred in storage containers in the temporary housing but some Ae. albopictus did so in village areas. The questionnaires indicated a significant difference between residents of temporary housing and villages in response to the question: Do you know where mosquitoes breed? The proportion of the “wastewater pools” response was higher among temporary housing residents than among village residents. This knowledge among temporary housing residents may relate to the fact that wastewater pools are latent breeding sites for mosquitoes in temporary housing sites. Although residents in the temporary housing sites put salt and abluent into storage containers to prevent mosquitoes from breeding, wastewater pools receiving a constant supply of wastewater provided the best breeding site for mosquitoes.