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expert reaction to hot weather this week, and heat-health alert from the UKHSA

Expert comments on the expected hot weather this week, and a heat-health alert from the UK Health Security Agency (UKHSA).


Dr Radhika Khosla, Director of the Oxford Martin Programme on the Future of Cooling and Associate Professor at the Smith School of Enterprise and Environment, University of Oxford, said:

“The health implications of rising temperatures in the U.K. are serious. Important physiological changes occur in response to high temperatures including changes in our circulatory, nervous and respiratory systems.

“When these adaptive measures are not enough, the risk of cardiopulmonary and cardiovascular problems increases among older adults, young children, people with chronic conditions, athletes, and outdoor workers.

“Severe heat disrupts sleep, impairs cognitive performance, and is associated with increased risk of suicide or hospital admission for mental illness.

“But increasing heat is not just an immediate health risk. It also has a detrimental effect on the economy and livelihoods, infrastructure, education, poverty, food and nutrition, and gender equality. The Government should focus on:

“• Implementing heat-health action plans coordinated across departments and implemented with clear communication strategies, real time surveillance, and local and national evaluation

  • Introducing natural cooling solutions to urban built environments such as increasing use of tree cover, water bodies, and reflective surfaces that mitigate heat exposure in cities
  • Promoting cooling behavioural strategies such as changing dress codes and times of work.

“These low energy solutions help reduce health risks without worsening climate change. In contrast, energy intensive air conditioning, likely to be the world’s primary heat reduction strategy, exacerbates global warming and drives further extreme heat events, while remaining unaffordable for the estimated two to five billion people who will be exposed to heat stress by 2050.

“The global community must commit to sustainable cooling, or risk locking the world into a deadly feedback loop, where demand for cooling energy drives further greenhouse gas emissions and results in even more global warming.”


Prof Hannah Cloke, University of Reading, said:

“While some of the advice on avoiding heatwave risk may seem like stating the bleeding obvious, it can genuinely save lives. Most people are able to stay out of the sun, drink more water and avoid strenuous activity, but for some people who may be stuck in a boiling hot flat, with health problems and unable to cool down, the effects can be lethal. We need to check on vulnerable people, as well as improving buildings, infrastructure and daily schedules to avoid heat risks.

“Despite the official warnings, some people still underestimate the effects of heat and don’t change their plans to take it into account. We need to consider how people react to the current warnings, and continue to improve them. A warning system that people ignore is next to useless.

“Thousands of people already die due to excess heat in the UK, and climate change will only make heatwaves more frequent and more extreme in the future. Let’s not wait for people to die before we take heatwaves seriously.”


Jason Kelly, Deputy Chief Meteorologist, Met Office, said:

“The heat is a result of a mix of home-grown warming due to a high pressure over the southern half of the UK, as well as a south westerly airflow bringing warm air, which has been over continent through the week, across the country.

“This is the first spell of hot weather this year and it is unusual for temperatures to exceed these values in June. Some areas may see warm nights with minimum temperatures expected to be in the high teens or even low 20Cs overnight, especially in urban areas such as London.”


Dr Vikki Thompson, Climate Scientist at the University of Bristol Cabot Institute for the Environment, said:

“Climate change is making heatwaves hotter and last longer around the world. Scientists have shown that many specific heatwaves are more intense because of human-caused climate change. The climate change signal is even detectable in the number of deaths linked to heatwaves. Here in the UK the hottest day of the year is, on average, nearly 1°C warmer than in the 1970s. Across Britain extended periods of hot weather have doubled in length since the period 1961-1990. South East England has seen the greatest changes – with a tripling of warm spells. 

“The UK record temperature for June is 36.6 °C from Southampton in 1976. The Met Office is currently forecasting highs of 34 °C on Friday.

“Heatwaves are one of the most deadly natural hazards, in the UK ~3000 deaths were linked to heatwaves in 2021. The health issues related to heat include direct effects, such as heat stroke and cardiovascular failure, and indirect effects including poorer mental health and an increase in accidents such as car crashes and drownings. To keep safe make sure you stay cool, drink plenty of water, and wear suncream. Look out for the more vulnerable such as young children and older people.”


Dr Friederike Otto, Senior Lecturer in Climate Science, The Grantham Institute for Climate Change, Imperial College London, said:

“Climate change is a real game changer when it comes to heatwaves, they have increased in frequency, intensity & duration across the world because of our burning of fossil fuels. Trends in heat extremes are particularly strong in Europe though, where many studies have shown that they have increased in frequency by a factor of 100 or more due to human-caused climate change.”


Kirsty McCabe FRMetS, Royal Meteorological Society, said:

“The last time we saw temps over 32C was on 20th July 2021 when we recorded 32.2C at Heathrow.

“The last time we saw temps of 33C or over was back on 12th August 2020.

“We didn’t see temps above 33C at all last year the highest temp was the 32.2C recorded at Heathrow on 20th July last year.

“33C or higher in June is rather exceptional, especially this early in the month.

“The most recent 33C in June was Heathrow reaching 33.4C on 25th June 2020.

“We did reach 33C in June in 2017, 2018, 2019 and 2020, but all of them were after the 20th.

“33C has only been recorded before the 20th on a handful of occasions.

“Should we get to 34C, the last time 34C was reached in June was 2019 when Heathrow and Northolt both reached 34.0C on 29th June. In 2017, 34.5C was reached at Heathrow on 21st June.

“During the 1976 heatwave, 34C or more was recorded at multiple sites on 3 consecutive days but since then it has only happened twice (as above).

“Historically, 34C has only been seen before 20th June once, on 3rd June 1947.

“The UK’s hottest June day on record is 28th June 1976 with 35.6C at Southampton Mayflower Park.

“Maxima of 33C or more in June have occurred on less than 1% of June days since 1961 with 34C or more registered just 5 times in June since 1961, mainly in the exceptional heat of late June 1976.”


Dr Mark McCarthy, head of the Met Office National Climate Information Centre, said:

“Climate change has increased the average temperature of UK summers, and it is also increasing the likelihood of experiencing more extreme temperatures during hot spells and heatwaves.

“Reaching 34C during June is a rare, but not unprecedented, event in the historical climate records for the UK.  But if it should happen this week it would be notable that it would have occurred on three days during the last six Junes.”  The other days being 21 June 2017 and 29 June 2019.

“Before that the only June exceedances – when England saw a number of stations reach 34C or higher – were 3 June 1947, 29 June 1957, and 26-28 June 1976: a notoriously hot summer.”


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