Adverse weather is important to our health: There is a strong evidence base showing us that periods of very hot or cold weather or flooding present a wide range of direct and indirect health risks.
We know that climate change is making these problems worse by increasing the number of adverse weather events, and these events will become more frequent and intense in the coming years.
But there is much we can do to address this problem, taking steps to reduce health risks and adapting our behaviors and environments to our changing climate.
Here at UKHSA, we play a key role in providing evidence and advice to help policymakers, organizations and individuals to do just that.
The risks to our health due to adverse weather
Summer is coming and most of us are looking forward to some sun and warmer weather.
But as scientists working to protect people’s health, we know that not everyone does well when temperatures rise, and periods of hot weather are linked to increased health risks, as well as increased pressure on our system. social and health care.
The health dangers of heat
Temperatures above 25ºC are associated with excess heat-related deaths, and higher temperatures are associated with even higher numbers of excess deaths. The risks are higher for people with certain conditions:
At 27ºC or higher, people with impaired sweating mechanisms find it especially difficult to keep their bodies cool (for example, the very young, people with long-term health problems, or the elderly, particularly people taking certain medicines).
Heat can exacerbate cardiovascular and respiratory conditions in the long run, but it can also increase the chances of other sudden and serious health problems, such as heart attacks, strokes, or respiratory problems.
Mortality impacts during periods of hot weather are generally seen within 24 hours of the onset of high temperatures, with daily deaths increasing as temperatures rise and then declining as temperatures return to low. their average levels.
During last year’s heat spells, the hottest on record, we saw thousands of heat-related deaths, each a human tragedy, also placing significant pressure on our health and care services.
The dangers of the cold
There is an equally strong evidence base on the health risk of cold weather, again with older people (people 65 and older) and those with some long-term medical conditions facing the greatest risk. Energy poverty exacerbates this situation.
Direct effects of cold weather include: increased incidence of heart attacks, strokes, respiratory illnesses, influenza, falls and injuries, and hypothermia.
The onset of cold weather leads to an almost immediate increase in weather-related deaths, which can remain elevated for up to four weeks afterward. Deaths from cardiovascular conditions peak first, followed by stroke and then respiratory conditions. Negative health effects begin with relatively moderate outdoor average temperatures of 4 to 8 °C.
floods and health
Floods also have widespread and significant health impacts, including direct effects such as skin and intestinal infections from exposure to contaminated flood water.
And while the immediate and direct impacts of very hot or cold weather and flooding are perhaps the most obvious, we must not forget the longer-term or indirect impacts.
Heat, cold and flooding are linked to mental health problems, for example (in England, most of the health burden associated with flooding is due to the impacts of flooding on mental health and well-being, ranging from stress and anxiety to serious long-term impacts) .
Living in cold homes is linked to reduced education and employment.
Both cold weather and flooding are linked to respiratory illnesses caused by mold and damp.
What is the impact of our changing climate?
The last decade has seen warmer and wetter weather than previous decades. The number of heat-related deaths is projected to triple by 2050, with the hottest summers on record we’ve observed in recent years becoming just “normal” summers.
Last year in Lincolnshire the temperature hit 40.3°C, beating the previous UK record by 1.6°C, and the hot spell in July saw the Met Office issue its first red warning for extreme heat .
At the time, Dr Mark McCarthy of the Met Office’s National Climate Information Center noted that “in a climate unaffected by human-induced climate change, it would be virtually impossible for temperatures in the UK to UK reach 40°C, but climate change is already making the UK have more frequent, intense and long-lasting heatwaves.”
In terms of flooding, the third UK Climate Change Risk Assessment in 2021 identified flooding as one of the most significant climate change adaptation challenges facing the UK. Under all future climate change scenarios, direct and indirect flood risks are projected to increase throughout the 21st century.
Many people might wonder if warmer weather in the UK means that there will be less illness and death from cold weather in the future.
The effects of climate change on cold-related illnesses and deaths could have some benefits, but projections suggest that the total number of cold-related deaths each year is unlikely to decline significantly due to problems such as substandard housing and shortages of fuel.
This means that although average temperatures are expected to rise, cold will remain a major public health concern for years to come.
Protect communities and public services from adverse weather
An important role for the UKHSA is to monitor the health effects of adverse weather and our changing climate in general, and to provide advice and guidance on how we can adapt to meet these challenges.
It is very important to reinforce that the damage to health associated with adverse weather is not inevitable. There are things we can do throughout the year and during periods of adverse weather to minimize the impact.
We recently published a new Severe Weather and Health Plan as part of our commitment under the second National Adaptation Program for the UK to bring together and improve existing weather and health guidance.
We also publish a series of ‘action cards’ advising the NHS, social care organizations and professionals on the actions they need to take to keep the public healthy and safe under different levels of alert.
Our guidance also includes tips that the public can follow to stay safe, and as always, our most important call to action during severe weather is to look out for those who may be struggling to cope, particularly seniors. , young children and people with long-term problems. healthy conditions.
Thinking in the future
Globally, climate change poses one of the biggest health security threats we face, affecting the air we breathe, the quality and availability of our food and water, the risk of infectious diseases, and impacts broader in our mental health and well-being.
This summer, the UKHSA will publish the Health Effects of Climate Change, a landmark report produced regularly and last published in 2012. This will bring together the latest UK climate change projections and an assessment of the range of health risks.
In addition to publishing this evidence on climate threats to health, UKHSA’s new Center for Climate Safety and Health will continue to provide focus for our climate health partnerships, offering scientific advice and support to ensure that the impacts of climate change are considered and incorporated into the design. and climate change policy delivery through local and national government and the NHS, as well as with international partners.