Preparing for heat risk is complex: Aligning adaptation and mitigation is essential

Why should the UK be concerned about heat risk?2023 was the warmest year on record with a global average temperature of 14.98˚C: 1.48˚C above the 1850-1900 baseline 1.In the UK, 2022 was the warmest year on record, and 2023 the second warmest 2.The target to limit the increase in global average temperature to well below 2˚C above pre-industrial levels, as outlined in the Paris Agreement, is growing in urgency, particularly as the interim goal to 'pursue efforts' to limit that increase to 1.5˚C is on our doorstep 3.On 19 July 2022, the UK experienced temperatures over 40˚C for the first time, the UK Met Office issued its first ever red 'extreme heat' warning resulting in the Government declaring a national emergency.The five heat periods that summer led to almost 3,000 heat-related deaths in England 4, the highest number since the introduction of the 2004 Heatwave Plan for England.Without adaptation, and under a high emissions scenario, scientific evidence shows that UK heat-related deaths are estimated to increase by almost 166% (4,266 total deaths per year) in the 2030s, 580% in the 2050s (10,889 total deaths per year), and 1,244% (21,545 total deaths per year) in the 2070s, above a 2007-2018 baseline 5.The heatwave in England in 2022 was a 1-in-1,000 year event, made ten times more likely due to anthropogenic climate change 6.The impacts to the UK go beyond affect physical and mental health.Extreme heat affects the economy: over 11 million potential labour hours were lost in the UK in 2022 because of heat exposure across the agricultural, construction, manufacturing, and service sectors.This is further compounded by the design of buildings in the UK which has primarily been aimed at protecting from the cold rather than mitigating the impacts of heat.Rail and road infrastructure are affected by high temperatures in a number of ways leading to higher speed restrictions, delayed and cancelled routes, road closures and congestion where road users then become further exposed to extreme heat and wildfires in stationary vehicles.Water and energy infrastructure can be affected by a surge in water and energy demand for cooling, as well as power cuts due to pole-mounted transformers and overhead conductors overheating.Heat stress affects the natural environment causing animal casualties and damage to plants, flowers, trees and habitats, further increasing the risk of grass and wildfires.This also affects nature's ability to produce crops (impacting food production, disrupting supply chains and affecting food prices), and can reduce the shading and cooling capacity of trees, plants and green spaces 7.Whilst summer 2022 broke records, and summer 2023 was far less extreme for the UK, heatwaves are projected to become more severe, longer and frequent in future.But we should also consider the impacts of heat at lower temperatures, as we don't need to experience 40˚C heat to see significant health impacts, particularly as most buildings in the UK are not