The distribution of overall temperature and the frequency of heat waves maybe shifting due to climate change. However, forecasting future health consequences of higher temperatures in a given city is complicated by uncertainties in how populations and societal infrastructure will adapt. This paper reviews approaches to address these challenges, including: (1) using historical weather-mortality relationships for the same region, or a location with a similar climate as the city of interest; (2) evaluating adaptation using the minimum mortality threshold (MMT) temperature (i.e., the temperature with the lowest mortality rate); and (3) estimating the impact of modifiers (e.g., air conditioning, population density, green space) on the temperature and mortality relation, and then predicting a range of effects based on plausible estimates for the future values of these parameters in a given city. Each approach can provide insight into how heat could affect mortality under a changing climate, but all have uncertainties. In spite of these limitations, projecting the future public health burden of temperature-related health effects can provide valuable information to aid public health and environmental authorities in planning and communicating the risks of climate change to the public. (c) 2007 Elsevier Ltd. All rights reserved.