Climate change may increase the number of heat-related deaths in the UK by 540%, health experts predict.
By 2080 almost 11,000 people could die every year as a result of heatwaves, up from 2,000 at present, as extreme weather becomes more commonplace, according to the Health Protection Agency (HPA).
Rising temperatures could also mean that British people may contract exotic illnesses at home as mosquitos carrying tropical diseases, such as dengue fever and chikungunya, could migrate to the UK.
People with hay fever will have a protracted period of suffering each year as the warmer climate could mean that the pollen season starts earlier and finishes later.
A report by HPA, based on the latest climate change projections for the UK, suggests that the health burden created by cold weather could decline by 2080 compared with the present day as average temperatures are expected to rise between 2C and 5C.
Heatwaves are likely to cause more premature deaths, increasing by 70% in the 2020s and by 540% over the next 70 years, the experts predict.
The report, presented at the HPA annual conference at the University of Warwick, also concludes that because elderly people are more vulnerable to extreme heat, health burdens are likely to be amplified by an ageing population.
HPA chairman Dr David Heymann said: "There is no doubt that climate change poses a wide range of challenges to public health in the UK. From increased risks of heatwaves through to potentially greater exposure to air pollution, indoors and outdoors, and potential changes to established pollen seasons, there are many issues, all of which need further research and attention if we are to adapt to or mitigate the effects.
"We are confident that this report will provide all government departments with the further information they need to properly prioritise areas for future work and protect the UK public from the significant looming health challenges that climate change presents."
Professor Sir Andy Haines, HPA climate change chief, said: "If we as a nation are to minimise the health effects of climate change in the UK, it is critical that we consider potential impacts on every aspect of life and invest in research to improve our understanding.
"This report shows that in the UK, climate change is likely to have a range of effects on health and that we can anticipate and prepare for some of these effects. However, it also suggests that well-designed policies to reduce greenhouse gas emissions in sectors such as electricity generation or transport can have important ancillary benefits for health, for example by reducing particulate air pollution and increasing physical activity."