Prof Kris Ebi from the University of Washington started off the third day of the conference with a presentation on heatwaves and early action plans. She pointed to the 2021 Pacific north-west “heat dome” event, which resulted in around 800 excess deaths and was later found to be a 1-in-10,000 year event. The rarity of that event means, in effect, “these people died because of climate change,” Ebi said. She added: “Every heat-related death is preventable.”