If hotter weather really results in more deaths, then the sun must have wreaked carnage in Faversham in Kent when temperatures reached 38.5ºC in August 2003. But even this, the highest temperature since records began, didn't appear to cause mass destruction. We try to find out why.
Up to 760 people dead so far
Figures in the Times today estimate that as a result of the temperature, anywhere between 540 and 760 people have died in England alone in the space of nine days.
That seems surprising for a number of reasons:
1. There are lots of different things listed as 'cause of death', including 'influenza', 'senility' and 'malignant neoplasms' in national statistics. Neither 'sun' nor 'heatwave' are on the list.
2. Perhaps then, the statisticians looked at causes of death such as 'asthma' or 'pulmonary disease' that might have been aggravated in raised temperatures. That seems unlikely given that these statistics are released on an annual basis and statistics for 2012 were only just released a week ago.
3. Maybe, noticing this timing problem, the statisticians issued freedom of information requests to every coroner in the country. That's not only unlikely but also inaccurate - it can take up to five days to register a death, so the information received wouldn't be sufficient to understand what the mortality figures of our nine-day heatwave are so far.
One other method seems plausible: perhaps the researchers looked at the number of Brits that die each year and compared that to the number of heatwaves or average summer temperatures. Their chart would look something like this:
The correlation doesn't appear to be too strong. There is another problem when we look at published national statistics on death - there are fewer in the summer months.
That might be because vulnerable groups like the very young and the very old actually spend less time outside when the weather is exceptionally hot. Or it could be that winter temperatures represent a more serious health concern. Or it might just be that there are other factors that play a larger role in determining our death than sunshine alone.
But let's assume that the researchers also controlled for a couple of things to be able to observe the effects of temperature. That would mean they've been able to take things like demography, changes in the provision of drugs and healthcare services out of the equation, as well as any diseases or viruses that may affect the number of deaths that are registered. That would allow them to really hone in on what the heatwave is doing to us.
If that were the case, they must have noticed a spike in the number of deaths, or to be more precise, predicted an increase. That 'spike' consists of 540-760 people of a total of about 110,000 deaths on average in England and Wales between June and August each year.
But averages don't always mean a lot - unless you're measuring something like the number of hours in a day, you'll always get numbers that differ from an average. Which leaves the question - is a 0.7% increase a cause for concern?
What do you think? Share your views below
Update: The author of the original article has responded to this piece - you can read his reaction here