At least three hospitals have declared critical incidents as the UK endures a historic heatwave, with temperatures reaching record highs. The Met Office issued a rare red warning for extreme heat, placing significant strain on NHS services.
Critical incidents declared in Portsmouth and Norfolk
On Wednesday, June 24, Queen Alexandra Hospital in Portsmouth and Norfolk and Norwich University Hospitals NHS Foundation Trust (NNUH) both declared critical incidents as temperatures soared to 36.1C. The following day, which provisionally became the UK's hottest June day on record, University Hospital Southampton also declared a critical incident due to ongoing extreme heat.
Chiller failures at Queen Alexandra Hospital
At Queen Alexandra Hospital, the critical incident was triggered by the failure of several chiller units supporting critical infrastructure. Although the units were restored, the extreme heat slowed the cooling process, prolonging the incident. Michelle Stanley, acting chief executive of Portsmouth Hospitals University NHS Trust, stated: “Our teams have worked hard to fix the initial issue and our chillers are now back and working. However, the extreme heat means the process of cooling key infrastructure is taking longer than hoped.” Some planned care and appointments were postponed until temperatures stabilised.
MRI scanner cooling failures at NNUH
At NNUH, the critical incident resulted from cooling system failures in MRI scanners. A mobile unit arrived on Thursday, and the trust is working to reschedule 362 cancelled outpatient appointments. Chris Cobb, NNUH chief operating officer, said: “We have worked tirelessly in the last 24 hours to bring some of the scanners back online. This morning we have received a mobile unit and we now have working scanners across the trust.” He added that emergency departments and urgent care were unaffected, and affected patients would be prioritised by urgency.
Southampton cancels operations and appointments
University Hospital Southampton cancelled a number of planned operations and outpatient appointments. A statement read: “Our priority is patient safety and the welfare of our staff and we are asking for the public’s support during this time.” The trust did not specify how many appointments were affected.
Impact on patients and services
The heatwave has disrupted hospital services across the south of England, with patients facing cancellations and delays. The NHS is working to restore normal operations, but the extreme weather continues to pose challenges. The Met Office's red warning remains in effect, urging the public to take precautions.



