Hospitals in England declare critical incidents as heatwave disrupts equipment and IT

Heatwave disruption hits hospitals

Multiple hospitals in England declared critical incidents on Thursday after extreme heat and humidity began breaking down cooling systems, scanners and digital infrastructure, forcing cancellations and service changes across the NHS.

Queen Alexandra Hospital in Portsmouth was among the sites affected. Portsmouth Hospitals University NHS Trust said cooling units failed as temperatures rose through the hospital, disrupting digital systems and affecting critical clinical services, including operating theatres, cardiac catheter laboratories and diagnostic scanning facilities.

The disruption was not confined to one trust. The Royal Devon and Exeter hospital also declared a critical incident on Thursday evening because of the impact of extreme heat and humidity on its ability to deliver services.

At Norfolk and Norwich University Hospitals NHS Foundation Trust, cooling systems that keep MRI scanners running were affected by the hot weather and humidity. The trust said it had no working MRI scanners across its Norwich sites, including its main hospital and community diagnostic centre.

Services cancelled and scanners stopped

The loss of MRI capacity quickly fed through into patient care. NNUH said hundreds of patients had hospital appointments cancelled after the scanners stopped working.

The wider effect went beyond imaging. Reports from the affected hospitals described pressure on operating theatres, interrupted scanning and reduced resilience in the digital systems used to support everyday care.

The sequence of events highlighted how a heatwave can turn into an infrastructure problem. What began as a weather issue became a hospital operations issue, with cooling failures and IT disruption forcing trusts to scale back activity and protect essential services.

Official response

NHS England said hospitals were putting hot weather plans into action, including managing temperatures in clinical areas, supporting hydration and prioritising higher-risk groups.

The Department of Health and Social Care said all NHS trusts are required to have effective arrangements in place to deal with extreme heat.

Doctors quoted in the coverage said the heatwave was also adding broader pressure across the service, with more A&E attendances and overcrowded wards compounding the technical failures at individual hospitals.

What the heatwave exposed

The incidents point to a wider vulnerability in the NHS estate. Older buildings, cooling systems and IT infrastructure are being tested by prolonged heat and humidity, and several trusts found themselves unable to keep key systems running normally.

The immediate questions are how quickly the affected cooling and IT systems can be restored, whether more trusts will be forced to declare incidents if the heat continues, and how many more appointments and procedures will be lost before services stabilise.

For now, the impact is already concrete: cancelled outpatient appointments, suspended scans and disruption to clinical services at a time when demand on the NHS remains high.