Heatwaves are among the world’s deadliest weather hazards. Every year, vast numbers of people are killed by heat stress and it can worsen health problems such as diabetes, asthma and heart disease.

Shepparton is deep into a heatwave, a condition some attest exists when we have successive days of 35°C or more with accompanying warmer-than-usual nights.

A leading Victorian state high school, widely praised for its green “passive cooling”, cut classes ended early because the ...