Climate change predictions indicate more extremes in weather conditions in the coming decades with more frequent and severe heat waves in certain locations including Australia. It is likely that the more vulnerable members of the community will be at risk during heat waves in the future from both health and financial perspectives. The trend towards fully air conditioned larger homes has already seen very large peaks in electricity demand during past heat waves. Electricity prices have increased substantially in recent years and will increase further due to greater peak demand and environmental levies. To manage the risks to dwelling occupants during heat waves, research has been carried out to determine methods of promoting adaptive behaviours through residential design. This paper describes the concept of a “cool retreat” within a dwelling which can provide comfort conditions with minimal cooling costs during heat wave periods. The cool retreat concept is shown to have its origins in the past in a number of locations around the world subject to hot conditions. Various cool retreat configurations have been analysed for thermal performance, demonstrating the viability of this approach for dealing with extreme conditions in the future.