Should we embrace air conditioning despite its costs and consequences, and how much should we spend on adapting homes versus cutting carbon?

Mandy Bourne lives with her 80‑year‑old mum in a top‑floor social housing flat in the West Midlands. Both struggle with health conditions exacerbated by the recent heatwaves. For Mandy, temperature shifts can trigger flare-ups of her chronic lung condition. "I've got COPD and sometimes I can't breathe," she explains. Across the UK, solid brick homes like theirs quietly absorb heat the way they have for decades. Charged‑up walls radiate warmth back into rooms that never get the chance to cool. Mandy says she is constantly reaching for her inhaler as her flat overheats. "It's red hot in the flat. The sun is just beaming in." That retained warmth can push night‑time temperatures in urban centres up to 7C higher than the surrounding countryside. This is the urban heat island effect and it is at its most dangerous in the early hours when bodies need cooler air and cannot find it. Modelling of a previous West Midlands heatwave by researchers from the University of Birmingham reached the bleak conclusion that the heat island impact alone accounted for roughly half the 130 heat-related deaths. Jo Shields, head of sustainability for Mandy's housing association Walsall Housing Group, known as whg - which owns 23,000 homes across Walsall and the Midlands - hears the same complaint time and again. "The heat gain stays within the concrete or the brick," she says, "so the night-time cooling becomes harder". Last summer, as the region baked, the residents of Ellum Pointe - a whg scheme for the over-55s - began telling their landlords they simply could not cool their flats. The response was improvised. "We took the community room, closed all the windows and doors, and we put a mobile air-conditioning unit in there," Shields says. "And basically, we created an internal cool room." She likens it to the warm spaces opened during the pandemic for people who couldn't afford to heat their homes.