A spike in deaths resulting from Britain’s summer heatwave “can’t be ruled out yet”, an expert has claimed.

Nick Stripe, joint deputy director of health analysis and life events at the Office for National Statistics (ONS), dismissed as premature reports that heat-related deaths were soaring this year.

Months of blistering temperatures have fuelled speculation that the climate was to blame when registered deaths rose above average between June 2 and July 20.

The figure was 995 above the five-year average for the seven-week period in England and Wales.

But in an online blog, Mr Stripe warned this did not mean all the deaths took place during that time frame – instead reflecting when they were registered.

He wrote: “It is impossible to tell from the data currently available to us how many people actually died during this period and how many of those deaths were as a result of the heat.”

The total may therefore fail to reflect people who died during the seven weeks this summer, but whose passing was not registered until afterwards.

A more accurate figure for how many people died during the heatwave – and if the death was weather-related – will not be available until later this year, he said.

Registering deaths can be delayed when cases are referred to a coroner for investigation, which takes place when the cause is unknown or appears unnatural.

Britain has enjoyed weeks of uninterrupted sunshine this summer (Gareth Fuller/PA)
Britain has enjoyed weeks of uninterrupted sunshine this summer (Gareth Fuller/PA)

Mr Stripe wrote: “Although the provisional data currently available appear to show a high number, it’s not really clear how meaningful this is.”

Despite exceeding the five-year average, the latest death figures were below the number registered during the same period in 2017 and 2016.

This year there were 65,439 deaths registered, compared with 65,846 last year and 65,728 in 2016, according to the blog.

Both those years had also exceeded the rolling five-year average – with the seven-week period in 2017 recording 2,332 deaths above the five-year average at the time.

Public Health England (PHE) produces regular mortality estimates based on the ONS data, but it “has not yet observed a significant and sustained increase in mortality” for summer 2018, Mr Stripe said.

The hot weather could pose a health risk (Brian Lawless/PA)
The hot weather could pose a health risk (Brian Lawless/PA)

His blog continued: “However, it’s important to avoid complacency – hot weather can be challenging particularly to older people, young children and those with long-term conditions, including heart and lung diseases.

“Heatwaves are predicted to increase in frequency and intensity as a result of climate change.

“The main causes of death during a heatwave are respiratory and cardiovascular diseases.

“PHE estimated there were 908 excess deaths over the summer 2016 period in England.”