Climate change projections have drawn attention to the risks of extreme heat and the importance of publichealth interventions to minimise the impact. The city of Perth, Western Australia, frequently experienceshot summer conditions, with recent summers showing above average temperatures. Daily maximum andminimum temperatures, mortality, emergency department (ED) presentations and hospital admissionsdata were acquired for Perth for the period 1994 to 2008. Using an observed/expected analysis, the temperature thresholds for mortality were estimated at 34'36 °C (maximum) and 20 °C (minimum). Generalisedestimating equations (GEEs) were used to estimate the percentage increase in mortality and morbidity outcomeswith a 10 °C increment in temperature, with adjustment for air pollutants. Effect estimates arereported as incidence rate ratios (IRRs). The health impact of heatwave days (three or more days of'35 °C) was also investigated. A 9.8% increase in daily mortality (IRR 1.098; 95%CI: 1.007'1.196) was associatedwith a 10 °C increase in maximum temperature above threshold. Total ED presentations increased by4.4% (IRR 1.044; 95%CI: 1.033'1.054) and renal-related ED presentations by 10.2% (IRR 1.102; 95%CI: 1.071'1.135) per 10 °C increase in maximum temperature. Heatwave days were associated with increases in dailymortality and ED presentations, while total hospital admissions were decreased on heatwave days. Public health interventions will be increasingly important to minimise the adverse health impacts of hot weatherin Perth, particularly if the recent trend of rising average temperatures and more hot days continues asprojected.