Dr Lisa van Aardenne, the chief scientist of the University of Cape Town’s climate system analysis group, discussed the use and utility of thermal stress indices. She pointed out that, by the definitions of the universal thermal climate index, much of Africa is under heat stress most days of the year.  Van Aardenne noted that these indices have been developed from a European perspective and do not align with the reality on the ground in Africa. She added: “I’m very concerned that these indices are not fit for purpose here.”

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.”