The media reporting on the heatwaves hitting the northern hemisphere was unequivocal: the current record heatwaves were “pushing the limits of human survival”. Perhaps even more worryingly, “the UK could be too hot to handle within three decades”, which would surely worry the 97% of humanity that live in places with warmer summers than the UK. The good news: Britons won’t have to move to Sweden by 2050. The bad news: deadly heatwaves are already here, getting worse and could soon become a much bigger problem than they are in almost every part of the world today. Heat is a silent killer, responsible for more deaths than any other natural disaster: several severe European heatwaves in recent decades, including last summer, have claimed tens of thousands of excess deaths. (University of New South Wales)