Color value and solar transmittance τcl, reflectance ρcl, and absorptance αcl of clothing with different fabrics and luminance reflectance were measured in order to evaluate the effect of the different types of clothing on solar heat load received by the human body. Seven clothing were selected: 100% cotton T-shirt, 100% polyester T-shirt, 74% polyester/26% cotton T-shirt, 75% polyester/25% cotton mesh T-shirt, 100% nylon long-sleeved working shirt, 100% cotton sheeting working trousers and 60% cotton/40% polyester twill trousers. Mean skin temperature was calculated by using a simple model for predicting mean skin temperature based on solar operative temperature considering solar transmittance and reflectance of clothing. There was a liner relationship between luminance reflectance and solar reflectance and transmittance of clothing. The difference in solar reflectance of 100% cotton T-shirt and the others was less than 0.1. The difference in the solar transmittance of 100% cotton T-shirt and the others was distributed within +/-0.1. Mean skin temperature was calculated in the following case: case Ⅰ) τcl, ρcl, αcl of 100% cotton T-shirt, case Ⅱ) ρcl, τcl+0.1, αcl-0.1, case Ⅲ) ρcl, τcl-0.1, αcl+0.1. Mean skin temperature in case Ⅲ was lower than the others. This result indicates that decreasing solar radiation absorbed by skin surface decreases solar heat load received by the human body.

DESCENTE SPORTS SCIENCE Vol.32/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE