London hospitals recorded more than 260 "overheating incidents" over 12 months amid rising temperatures, a report has found, as a senior doctor warned of the "dangerous" consequences of climate change on the NHS.
Analysis by not-for-profit Round Our Way found that a total of 269 "overheating incidents" occurred in the year up to March 2022 in the capital.
The figures are likely to significantly increase as they do not cover the period from June until August last year when the UK experienced its most severe heatwave on record, with temperatures surpassing 40C.
An "overheating incident" is when an occupied ward or a clinical area's daily maximum temperature exceeds 26°C - and triggers a risk assessment to ensure the safety of vulnerable patients.
Some of the reported impacts include patient distress, failure of essential equipment such as refrigeration, disruption to IT and laboratory services, staff discomfort and degradation or loss of medicine.
High temperatures also pose an occupational health risk to already stretched NHS staff, with prolonged exposure to extreme temperatures shown to decrease cognitive ability.
The report found that recorded overheating occurrences had doubled over the past five years across England. Last year also saw 2,895 heat-related deaths, the highest number on record, according to data from the UK Health Security Agency (UKHSA).
The Barnet Enfield and Haringey Mental Health NHS Trust emerged in the report as having one of the worst rates of overheating at NHS sites in the UK - with 80 incidents reported at hospital wards and surgeries.
Meanwhile there 41 incidents at the King's College Hospital NHS Foundation Trust and 27 at the East London NHS Foundation Trust.
The figures come ahead of a weekend of hot temperatures in the capital, with the mercury rising as high as 29C on Sunday.
In a statement on Thursday, the Met Office said that summer temperatures London could be like Nice in 50 years' time if carbon emissions continue to rise at their current rate.
Jeff Knight, of the forecaster's climate variability modelling team, said the "the central estimate of temperature increase by 2070 is about 4C in southern England".
Sandy Robertson, an emergency doctor and co-clinical lead at GreenED, said: "Excessive temperatures, particularly those surpassing 26°C, pose significant risks to the health and wellbeing of patients and vulnerable individuals. In such conditions, the body's ability to regulate heat becomes compromised, leading to a cascade of potentially dangerous physiological responses.
"Certain medications, including those for Parkinson's and MS, can hinder the body's natural ability to regulate temperature or increase sensitivity to heat, amplifying the risks associated with high temperatures. Additionally, some medications can cause dehydration or impair the cardiovascular system, which can further exacerbate the negative effects of heat stress."
Dr Robertson said that heatwaves also heighten the challenges faced by doctors working in emergency wards, putting them at risk of heat exhaustion and strokes while they attend to patients.
"Despite legal limits on working in hot temperatures, the reality in an emergency department is that our primary focus is always on helping people, regardless of the working conditions."
In July last year, two data centres at Guy's and St Thomas' Hospital failed during the heatwave - causing more than 100 delays to patients receiving care. It took six weeks before the system was fully restored and the response cost the hospitals £1.4m.
The British Medical Assocation's Chief Officer, Dr Latifa Patel said: "The sharp increase in the number of overheating incidents in hospitals is incredibly concerning and further evidence of the need for urgent investment in health service estates to modernise heating and ventilation systems and ensure vulnerable patients are not at risk.
"We need to ensure that the NHS can adapt to the increasing threat of climate change and this must be underpinned by sufficient capital investment to make buildings more energy efficient which will be more cost-effective in the long run and positively impact patients, staff and the environment."
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