The common belief that New Zealand's climate is mild appears to be supported by the statistics of deaths directly attributable to cold. However an initial analysis of seasonality of mortality using the modified Edwards method suggests New Zealand has a greater seasonality of mortality than the more extreme climates of the United Kingdom, the United States, Australia, Japan or Sweden. Examination of New Zealand monthly mortality from 1976 to 1986 suggests this is driven by the seasonality of mortality of those aged 65 and over. Three surveys of temperatures within New Zealand homes have suggested that few are fully maintained in the 18 degrees C to 24 degrees C comfort range. Mean temperatures close to or below 16 degrees C were found in two of these surveys. Further research is suggested to examine the links between health and housing thermal performance. This research should combine both health and building science knowledge and techniques.