A field measurements of the blood pressure change of elderly with the room air temperature change during the bathing were made in winter of Sapporo and Fukui. Average room air temperatures of the undressing room in Sapporo versus Fukui were 19.8 versus 12.6 degree-C. The temperature differences between the living and the undressing room in Sapporo versus Fukui were 2.7 versus 6.5 degree-C, respectively. It would appear that the insulation performance of houses in Sapporo is higher that in Fukui. Therefore, over the 5 degree of air temperature drop between the living and the undressing room brings about a terrible rise in their blood pressure at the probability of 80 percent or more.
