Field measurements were conducted in a nursing home located in the hot and humid city of Kumamoto, Japan, between July and September 2010. In addition, a questionnaire survey was conducted with care staff during the measurement procedure to evaluate the effect of the thermal environment on thermal comfort and productivity. Results indicated that radiant cooling and heating system provided a stable temperature. Furthermore, the system coefficient of performance was calculated to evaluate the performance of the radiant cooling system and was 1.8-3.1. As a result of the questionnaire survey, about half of the staff were satisfied with the current thermal environment in the facility, reporting that it was comfortable and did not reduce working efficiency.