Commenting on some negative effects of traditional conditioning strategies of indoor thermal environment in warm climates, the authors present a fundamental concept of thermal comfort and acceptability, new air-conditioning strategies by using fluctuating air movement based on the findings of human responses to transient thermal environment, and a prediction of energy saving caused by elevated indoor temperature settings. In addition, how to meet the requirement of providing human-beings a healthy, comfortable and affordable indoor air temperature, and to achieve a goal of sustainable development are also discussed in this paper. (C) 2004 Published by Elsevier B.V.