Can good design keep a heatwave out of your house?

We've just come through another week of record-breaking heat in the south-east, and it's exposing a hard truth: a lot of our homes simply aren't designed for the climate we live in.But this isn't just about being uncomfortable, extreme heat is Australia's leading cause of weather-related illness and death. So how can we design our homes so that they're a sanctuary once more, instead of an oven?