EHJ July 2005, pages 12-14

The heatwave in August 2003 killed more than 2,000 people in England, mostly among the over 75s. With UK temperatures reaching well into the thirties already this year, Nick Warburton reports on what contingency plans are in place to protect the vulnerable should a prolonged heatwave hit again

Picture this. It's a blistering hot August afternoon, there's not a cloud in sight and the world and his wife are packed like sardines on Brighton Beach, basking in the glorious Mediterranean style weather. Around the country, thousands throng to local parks and beaches to soak up the sun while pubs the length and breadth of the nation heave with lunchtime punters. The perfect summer idyll some would say.

But that's not the whole picture. Others are struggling to cope with the soaring temperatures, the stifling heat and suffocating humidity. Train lines buckle, transport grinds to a halt and hundreds of thousands of passengers face delays, stranded on buses, cars and trains in the sweltering mid-day heat. High levels of air pollution are recorded in London, Birmingham and other large cities, adding to the afternoon misery.

In this unforgiving climate, vulnerable groups like the elderly and the very young are among the first to succumb to the heat, and emergency services are called out to administer aid. Hospitals begin to admit scores of patients suffering with respiratory problems, from heat exhaustion and dehydration. The initial euphoria for the seasonal good weather soon wears thin, as the country lies sweltering under one of the worst heatwaves on record.

Though a rare occurrence here, severe heatwaves are likely to become much more common over the next 100 years thanks to climate change, so much so that by the 2080s, experts predict that an event similar to the one that hit England in August 2003 could take place every year. Even so, the short-term threat is still very real. Over the next couple of years, it's not inconceivable that England could face a repeat of the extreme weather that struck the country two years ago. And that could spell trouble for certain risk groups.

Older people, especially those over 75 years of age who live on their own or in a care home, as well as babies and very young children are among the most vulnerable when a heatwave strikes. Dehydration is a particular problem for these groups and the elderly are especially susceptible. As past experience shows, those living alone do not always receive the care they need, and may not be able to call for medical attention. Sometimes, elderly people have died at home without being admitted to hospital.

And there are others too whose health is put at risk. People taking certain medication, the bed-bound and those who rely on help from others to manage their day-to-day activities are all at risk from extreme heat.

Add to this, certain environments, which can exacerbate the risk from extreme heat - accommodation in top floor flats, lack of air conditioning and effective ventilation, or work places that produce extreme heat like foundries and bakeries. In fact, the built environment is a significant contributor to heat in the summer months when temperatures rise.

"Buildings take in heat during the day and you can get a boost of anything up to 10 degrees Celsius in the centre of major cities," explains Ian Bateman, climate change officer at Devon County Council, who refers to the urban heat island. This is when the building of large cities disturbs the weather and gives a location its own microclimate.

In an urban heat island, buildings and roads act like giant storage heaters. During the day, the huge concentrations of concrete, asphalt and bricks used in buildings and roads "soak up" heat and store it. The energy is then released at night. Heat islands can have a major impact on health by generating pollution and raising temperatures in the indoor environment.

Martin White, a senior consultant at the Building Research Establishment, has looked at ventilation in buildings and its effectiveness in countering heat gain. "One of the things about ventilation in summer is that you need much higher ventilation rates that you would require in winter," he says. "So, if in winter you are talking about one air change an hour in a particular room, in the summer, you're talking about ten."

Mr White says that in naturally ventilated buildings where there isn't a mechanical cooling system, companies should look to install solar shading or internal or external blinds to reduce the uptake of heat during the day.

The Health and Safety Executive provides useful information (see further information) on heat stress in the workplace as well as guidance for managers on workplace health, safety and welfare. It also plans to launch a new thermal comfort website in early July, which looks at employers' legal obligations. This will include draft guidance on the assessment, management and control of thermal comfort. The HSE is looking for feedback once it goes live.

The indoor environment is one area where EHPs could come to play a significant role in the long-term, particularly in the housing sector. The introduction of the housing, health and safety rating system later this year provides EHPs with an important tool in which to enforce housing improvements in relation to high indoor air temperatures. As Andrew Griffiths, CIEH's principal policy officer, explains excess heat is one of the hazards under the new system and EHPs would do well to refer to the HH&SRS guidance, which gives detailed information on the health effects of high temperatures, its principal causes as well as preventive measures.

Until the system becomes law, Mr Griffiths says EHPs should be on the look out for vulnerable groups and direct them to other local authority services, such as social services, which can provide support should a heatwave strike. After its introduction, however, EHPs can make a greater impact by ensuring remedial action is taken to counter excess heat, for example, by making sure adequate controls to heating systems are provided and that natural ventilation or air conditioning is properly installed and maintained.

There are other roles for EHPs - disseminating sensible advice, such as staying out of the sun, drinking plenty of fluids, preferably water or fruit juice and avoiding alcohol, and wearing light clothes. EHPs would also need to give additional advice on food hygiene, particularly barbecues.

Raising awareness now is important. When the last heatwave hit England two years ago, the impact on mortality and hospital admissions was profound. Research published in Health Statistics Quarterly found there was a large short-term increase in mortality, particularly in London, the worst hit region, where over 600 excess deaths were reported that summer. And that's not just deaths of people who would have died anyway over the next few weeks or months due to illness or old age. Evidence points to the uncomfortable truth that these summer deaths are "extra" and are the regrettable result of heat-related conditions.

In England, over 2,000 excess deaths were reported, the worst affected being the elderly, especially those over 75 years of age. In London, excess deaths for this group soared by nearly 60 per cent while excess hospital admissions of 16 per cent were recorded.

Perhaps more worrying is the fact that the excess mortality was much greater than in previous heatwaves. According to Health Statistics Quarterly, the 2003 event saw an estimated 42 per cent increase in mortality in London, compared to excess deaths of 16 per cent in 1995 and 15 per cent in 1976. Should a similar or more severe heatwave strike in the near future, preparations for meeting it will need to be in place and plans will need to work effectively should an emergency unfold. If not, the country could be faced with a major social, medical and political crisis.

While these figures make for a sobering read, England escaped lightly compared to some European countries. In France, the worst affected country, the authorities struggled to cope with the highest temperatures for 50 years. Exposed to unprecedented high day and night-time temperatures over a two-week period, medical services simply weren't prepared to deal with the extreme heat, which claimed 15,000 lives.

As had been the case in England, the burden of excess mortality fell most heavily on the over 75s. According to the Institute de Veille Sanitaire, more than 60 per cent of deaths took place in hospitals, private healthcare institutions and retirement homes. According to Sari Kovats, a lecturer at the London School of Hygiene and Tropical Medicine and a co-author of the Health Statistics Quarterly research, the north of the country was worse hit, in part because the buildings, unlike in the south of France, were not constructed for the sweltering heat. Also, the population was not used to dealing with such extreme hot weather.

For two days in August, Paris experienced night-time temperatures of 25.5 degrees Celsius, the highest ever recorded, and death rates more than doubled. One of the measures that French authorities have adopted to avoid a repeat of the disaster is the installation of a "cool room" in all residential care homes.

If the events of the summer of 2003 underlined anything, it was Europe's vulnerability to the effects of heatwaves on human health. A number of contributory factors were identified, namely the unexpected length and intensity of the heatwave, a lack of preparedness of healthcare and social systems for such an extreme event and the lack of community-based intervention plans. The events in France in particular, rang alarm bells across Europe and prompted many member states to review and even draw up their own heatwave intervention plans.

The Department of Health, which has recently updated England's own action plan, assures the public that the risk of a heatwave in England hitting this year being as severe as that in France in 2003 is less than 0.1 per cent. Even so, it does recognise that during relatively mild heatwaves, death rates are significantly raised. One of the core elements of the action plan is a "heat-health watch" system, which will operate from 1 June to 15 September each year. Based on Met Office forecasts for threshold day and night-time temperatures, the system will trigger four levels of response depending on the severity - awareness, alert, heatwave and emergency.

To run parallel as this system is operating, the Health Protection Agency intends to monitor the number of calls made to NHS Direct and the amount of visits made to a sample of GP practices. The idea is that daily and weekly call and consultation rates will be reported to the DoH to assess how people's health appears to be being affected by the weather.

While certain departments in local authorities, such as social services have a clearly defined role in the action plan's response, the role of EHPs has not been discussed in any real detail. Even so, EHPs should look to raise awareness of the dangers of excess heat and to disseminate relevant information. It's valuable advice that could save lives.

References

1. The Housing, health and safety rating system guidance
2. Protecting health and reducing harm from extreme heat and heatwaves, plan for England
3. HSE information sheet - heat stress in the workplace: what you need to know as an employer
4. Workplace health, safety and welfare: a short guide for managers