The number of hot weather days in England and Wales is expected to triple by 2080, which scientists warn will push up excess heat-related deaths by 257%.
In the study, researchers from the London School of Hygiene and Tropical Medicine and Public Health England used historic data on weather patterns and death rates to model the link between temperature and mortality.
They used this model with official predictions of climate change and population growth to predict the future number of excess deaths due to temperature over the next 75 years.
They estimated that by the 2080s there will be three times as many hot weather days and fewer cold weather days. While excess hot weather deaths will rise by 257%, excess cold weather deaths will fall by only 2%.
London and the Midlands are likely to be worst hit by the hot weather.
Although deaths from the cold will remain higher than hot weather mortality, protection against the heat will become vital for the elderly, researchers said.
The study authors warned: ‘As the contribution of population growth and ageing on future temperature-related health burdens will be large, the health protection of the elderly will be important.’