NHS Hospitals Declare Critical Incidents as UK Heatwave Breaks Records — MRI Scanners Fail and Hundreds of Appointments Cancelled

Several National Health Service hospitals across England have declared critical incidents after an unprecedented June heatwave caused cooling systems to break down, leaving medical equipment including MRI scanners completely non-functional and forcing the cancellation of hundreds of patient appointments. The crisis has exposed serious vulnerabilities in Britain's ageing public infrastructure and raised urgent questions about whether the NHS is equipped to cope with the increasingly extreme summers that climate change is delivering.

Record Temperatures Push NHS to Breaking Point

The Met Office issued a rare red warning for extreme heat as temperatures across England climbed to record levels for June. The mercury provisionally hit 36.1 degrees Celsius in Gosport, Hampshire  setting a new June record for the country  with forecasters warning that even higher temperatures were possible before the heatwave broke. The intense and humid conditions placed enormous strain on hospital buildings, the vast majority of which were constructed during an era when temperatures rarely exceeded 30 degrees Celsius in England.

A report published last year found that nine in ten NHS buildings across England are ill-equipped to handle prolonged periods of extreme heat. Wednesday's crisis proved that warning was not theoretical. As temperatures soared, cooling systems designed to keep sensitive medical equipment operating within safe temperature ranges began to fail under the sustained pressure of the record-breaking heat.

Hospitals Declare Critical Incidents — Scanners Down, Appointments Cancelled

Two major NHS trusts declared critical incidents on Wednesday as their infrastructure buckled under the heat. Norfolk and Norwich University Hospitals NHS Foundation Trust  one of the largest hospital trusts in England  declared a critical incident after its cooling systems failed, leaving the trust with no working scanners at all. Queen Alexandra Hospital in Portsmouth also declared a critical incident as its own cooling systems struggled to cope with the extreme conditions.

The consequences for patients were immediate and significant. At least 254 outpatient appointments were cancelled across the affected trusts as hospitals attempted to manage the crisis and prioritise the most urgent cases. Chris Cobb, Chief Operating Officer at Norfolk and Norwich University Hospitals, issued an apology to all patients affected and cautioned that the situation could take time to resolve, particularly while the extreme heat continued.

Beyond cancelled appointments, hospitals also faced surging demand for emergency care linked directly to the heatwave itself. Heat-related illnesses including exhaustion and dehydration placed additional pressure on already stretched accident and emergency departments, with NHS England warning that pressure on services was likely to intensify further over the coming days if temperatures remained at record levels.

A Crisis Decades in the Making

The NHS is far from alone in finding itself overwhelmed by Britain's increasingly extreme summer weather. Train operators across the country were forced to reduce speeds on multiple lines to prevent tracks from buckling under the heat, causing widespread delays for commuters and passengers. Schools described their Victorian-era buildings  many of which lack any form of air conditioning  turning into greenhouses as classroom temperatures climbed to uncomfortable and potentially dangerous levels.

The situation has prompted renewed warnings from engineers, climate scientists and public health experts that Britain's public infrastructure was built for a climate that no longer exists. The NHS in particular faces a structural challenge that cannot be solved overnight. Retrofitting thousands of hospital buildings with modern cooling systems capable of handling 36-degree summers would require billions of pounds of investment and years of work. In the meantime, heatwaves of the kind seen this week are expected to become more frequent, more intense and longer-lasting.

NHS England's accident and emergency departments recorded 2.45 million patient visits in May 2026 alone — the highest ever figure for that month. The additional pressure of a major summer heatwave arriving just weeks later has left many within the health service warning that the system is being asked to cope with more than it was ever designed to handle.

What the Public Should Know

With the heatwave expected to continue through Thursday and Friday at minimum, NHS England has issued clear public health guidance urging people to take precautions. Residents are advised to stay indoors during the hottest hours of the day, typically between 11am and 3pm, and to keep windows open where possible to allow air to circulate. Wearing loose-fitting, light-coloured clothing and drinking between 1.5 and 2 litres of water per day are also strongly recommended.

Those living near rivers, lakes or coastal areas have been warned to take particular care around open water. Despite the temptation to cool down by swimming in natural bodies of water, experts have highlighted the serious risk of cold water shock, which can cause sudden increases in breathing and heart rate and lead to panic even in experienced swimmers. The Royal National Lifeboat Institution has urged the public to enter open water gradually rather than jumping in.

For the most vulnerable  the elderly, young children and those with pre-existing medical conditions  the advice is more urgent still. Heat-related illness can develop rapidly and become life-threatening if not treated promptly. Anyone experiencing symptoms including dizziness, nausea, heavy sweating or confusion in hot conditions should seek medical attention without delay.