An environmental audit committee is calling for measures including the relaxation of work place dress codes amid the recent heatwave .
Heat-related deaths are set to treble by mid-century unless the Government takes action to tackle the dangers of soaring summer temperatures, MPs warn.
More than 2,000 people died in just 10 days in 2003 when a heatwave pushed temperatures to as much as 38.5C (101.3F), and the Met Office warns that hot spells of a similar intensity will occur every other year by the 2040s.
Without the Government developing a strategy to protect vulnerable people, such as the elderly, numbers dying from the heat could rise to 7,000 a year by 2050, a report from the parliamentary Environmental Audit Committee said.
Ministers need to "stop playing pass the parcel" with local councils and the NHS and take action to ensure homes, hospitals, care homes, offices, cities, water supplies and transport networks can cope with rising temperatures.
The report is published as the UK swelters in a prolonged heatwave hitting northern Europe, with scientists warning that climate change is making such heat extremes more likely.
Heatwaves cause premature deaths from cardiac, kidney and respiratory disease, put pressure on health and social services and hit wellbeing and productivity.
But MPs warned the public see heatwave warnings as "barbecue alerts", funding for local authorities to adapt to climate change has been withdrawn, and there is a lack of regulation to prevent new homes, hospitals and care homes from overheating.
There are also no regulations on maximum workplace or classroom temperatures, only 50% of UK motorways and major roads are surfaced with material that is most resilient to the temperatures the UK is increasingly experiencing, and efforts to stop cities overheating is not included in local or national planning.
The committee's report calls on the Government to take steps including:
- Ensure NHS England issues guidance to prepare the NHS for more frequent heatwaves, with NHS organisations submitting annual heatwave plans to more sure they are prepared.
- Make sure hospitals and care homes are inspected for their resilience to heatwaves.
- Change building regulations to make sure new homes and buildings do not overheat, and bring in stricter water efficiency standards to save water.
- Consult on introducing maximum workplace temperatures, especially for work that involves significant physical effort, while issuing formal guidance to employers to relax dress codes and allow flexible working during heatwaves.
- Issue guidance for head teachers about safe temperatures in schools and relaxing school uniform policy during hot weather.
- Review the capacity of local authorities to deliver on climate change protection, require them to report on what they are doing and introduce a green infrastructure target for cities to boost greenery such as trees and parks that can help cool urban areas.
- Assess the heat-related risks on public transport such as trains, which can be disrupted and create sweltering conditions during heatwaves, and potential economic losses.
- Launch a public information campaign on the growing frequency and intensity of heatwaves and run a year-round alert system to warn people about health risks.
Mary Creagh, chairwoman of the Environmental Audit Committee, said: "Heatwave warnings are welcomed as barbecue alerts, but they threaten health, wellbeing and productivity.
"The Government must stop playing pass the parcel with local councils and the NHS and develop a strategy to protect our ageing population from this increasing risk. "
She said the Government needed to do more to warn the public of the health risks of heatwaves.
And she said: "It must change building regulations and planning policies to ensure homes and transport networks are able to deal with extreme heat, and that local authorities and cities have green spaces and heat-resilient infrastructure."