Statistics show an extra 614 deaths have already been recorded this summer – and the number is set to increase as it does not take into account any fatalities from this week’s scorching 38.7 degree heat.
There are now fears the killer temperatures could see a repeat of the 2,000 deaths in 2003 – the last time the Mercury topped 38 degrees.
That year 2,139 extra Brits were killed due to the heatwave, Department of Health records show.
Now mortuaries and death registration offices are braced for another rush after Thursday saw the busiest day of the year for ambulance callouts.
Experts at The Grantham Research Institute on Climate Change and the Environment said “several hundred” or more heatwave deaths are projected due to Thursday’s temperatures.
Office for National Statistics showed 334 more deaths than average were recorded in England and Wales in the week to June 28 as a heatwave saw 30C highs.
And 280 additional fatalities were seen in the week to June 7, as a flaming start to June saw 29C.
And hundreds more deaths are expected in hot spells ahead in August. Office for National Statistics deaths totals for the past week are not yet available.
Health chiefs said most hot weather fatalities are the elderly, ill, vulnerable and babies.
Doctors say hot nights can be lethal as bodies suffer daytime heat stress but cannot recover at night.
Bob Ward, of the Grantham Research Institute on Climate Change and the Environment, said: “The 38C heatwave in 2003 caused more than 2,000 deaths in the UK.
“The death toll due to this week’s heatwave is expected to be several hundred, and we’ll have to wait to find out if it is higher than that as this heatwave was shorter than 2003.
“The spike in deaths at the end of June is also likely to be due to hot weather.
“Research suggests daytime deaths are due to hot weather worsening respiratory illnesses, while night-time deaths are often strokes.
“The combination of very hot days and very warm 20C nights is lethal as people’s bodies have trouble coming down.
“Anyone who has lost a relative will be asking ‘Was this death preventable?’
“The answer is we are not doing enough in this country to protect the vulnerable. The Heatwave Plan introduced after 2003 was the start, but we must do more.”
Public Health England’s Heatwave Plan for England 2019 said: “Excessive exposure to high temperatures can kill.
“Excess deaths are not just deaths of those who would have died anyway in the next few weeks or months due to illness or old age.
“There is strong evidence that these summer deaths are indeed ‘extra’ and are the result of heat-related conditions.
“The rise in mortality as a result of very warm weather follows very sharply – within one or two days of the temperature rising.
“At-risk groups include older people, the very young and people with pre-existing medical conditions, as well as those whose health, housing or economic circumstances put them at greater risk of harm from very hot weather.”
The heatwave before the weekend saw an amber level 3 Government heat health warning ordering hospitals to expect to be busier than usual and compelling health staff to make daily contact with the ill, vulnerable and elderly.
Despite a washout weekend Britain is set to bake again in three more Saharan heatwaves after the hottest July day ever.
Temperatures are not expected to reach last Thursday’s high of 38.1C but will peak at an similarly toasty 35C next month.