GCHU Blog: Cold homes and warm hearts

GCHU Co-Director Professor Carl Heneghan and Dr Tom Jefferson analyse the Health effects of indoor temperature on older people and children, and of the impact of household improvements in this latest GCHU blog.

This article was co-written by GCHU Co-Director Professor Carl Heneghan and Dr Tom Jefferson

This article was first published on Trust the Evidence Substack page, which you can subscribe to here.

As the energy crises bites and taxes are increased, the poor are becoming poorer, and winter envelopes the country, we thought it was about time to look at the evidence of the effects of cold homes on health. 

We did the usual search and got 47 hits. We’ve put the full table on the Open Science Framework (https://osf.io/dzmbp). 

We looked at the effects on older people and children and the impact of household improvements. And due to the paucity of evidence, we’ve set out several questions that need addressing.

The agencies and guidance make several important points. In March 2015, NICE suggested that a single-point-of-contact system should be set up to help warm homes. 

Age UK considers the cost of cold homes to the NHS was £1.36bn in 2016 per year. Given heating was much more affordable than it is now, and with costs out of control, this estimate requires revisiting.

You’d think there would be a coordinated system to ascertain the number of deaths from cold homes. Yet, the estimates vary considerably. In 2015, ONS figures report over the winter of 2014/15, there were 40,800 excess winter deaths in those over 65s from cold-related illnesses. ONS figures for 2019/20 reveal 28,300 more winter deaths in England and Wales, of which Age UK considered 8,500 deaths were due to cold homes.

Health effects of indoor temperature on older people

A systematic review of the minimum indoor temperature threshold recommendations for English homes in winter included 20 papers. The review was undertaken by the now defunct Public Health England (PHE), which reviewed the evidence for the Cold Weather Plan for England, which had recommended minimum indoor temperatures of 18 °C for bedrooms and 21 °C for living rooms. Two other studies stood out.

One pointed to an indoor temperature of 18 degrees being the absolute minimum compatible with lower mortality. The other showed that fit women aged over 75 were slowed down, and their ability to carry out home chores was impaired when the indoor temperature went as low as 15 degrees. Poor housing, poor ventilation, mould, dampness, poor or no heating and residence in a nursing home were all associated with a higher death toll. 

However, the evidence was limited for minimum temperature thresholds for homes. One of the most studied areas was blood pressure. which is shown to increase at indoor temperatures below 18 °C. Laboratory studies also suggested exposure to cold increases blood pressure and the risk of blood clotting. The evidence for indoor temperature thresholds on patients’ chronic illnesses was scarce. The report concludes that health effects start to occur at around 18 °C, and older people were less able to perceive low temperatures, and effects in this age group were more profound. The review did not find robust evidence to propose recommendations above 18 °C for older people.

Health effects of indoor temperature on children

A systematic review of climate change adaptation measures for childhood asthma: included 20 studies. Several randomised controlled trials showed improving ventilation and installing home heating is likely effective for relieving childhood asthma symptoms, especially in winter. The one trial in asthmatic children had a low response rate but showed better heat and decreased school absences in the children. Yet again, we find ourselves with a life-altering problem area where high-quality research is missing. The review concludes further research is urgently warranted to evaluate the impacts of adaptation measures on childhood asthma. 

Impact of household improvements

A systematic review of the health impacts of housing improvements. The review included 45 studies, the earliest from 1938 and the most recent from 2007. General, respiratory, and mental health were improved following warmth improvement measures with no harmful effects.

What’s concerning about the evidence base of whether housing has an impact on health is how little we know. Studies are inconsistent and systematic reviews point to the need to do more research. It seems essential to understand the effects of chronic diseases, particularly chronic respiratory diseases and cardiovascular diseases.

So after the misery imposed by Covid control measures and the bloodbath of abandoned elderly in nursing homes after seeing their society disintegrate, what can we do to help those most in need? 

If you want to know how bad it can get, then look at the impact of a severe winter on an unprepared civilian population in Oxfordshire in 1981-82. During the winter, 18 patients with frostbite were referred to the Peripheral Vascular Service – all had frostbite of either feet or fingers, some both.

We consider there are several vital questions that need addressing.

  • Has anyone seen a system for advising the public, as NICE suggested?
  • What are the most basic, cost-effective interventions to keep houses warm?
  • Why does the government not keep estimates of poor housing and cold homes up to date if it makes such a difference to health and costs?
  • Why are the estimates of excess deaths due to cold left to a charity, and why isn’t there a robust epidemiological approach to understanding the extent of the problem?
  • With the demise of Public Health England, whose responsibility is it to keep the evidence for indoor temperatures and health effects up to date? 
  • What are the effects of temperature thresholds in those with chronic diseases, and what should be the minimum temperature?

The government’s answer is to ask, ‘the public will be urged to turn down their thermostats by two degrees this winter.’ Yet, no one is interested in the effects on the most vulnerable; those out of sight are out of mind. Many won’t be able to turn their heating on in the first place, let alone turn it down. This issue needs a serious research program to address the problems and deliver cost-effective interventions. 

For example, if maintaining a constant home temperature of at least 18 degrees prevents morbidity and deaths, should we not provide a realistic allowance to cover all heating costs to those most in need? If proven to be cost-effective – then we might consider heating prescriptions. In the meantime, the vulnerable will be left shivering in the cold: the NHS will be left to pick up the bill.