ENGLAND — Several NHS trusts in England have declared critical incidents as a direct result of extreme heat. The heat caused failures in cooling systems, medical equipment, and critical IT infrastructure in some NHS hospitals.

The Queen Alexandra Hospital in Portsmouth declared a critical incident after extreme heat caused cooling units to fail. The failure affected digital systems, operating theatres, cardiac catheter laboratories, and diagnostic scanning facilities. Some planned care and appointments were cancelled at the hospital. Mark Orchard, the deputy chief executive of Portsmouth Hospitals University NHS Trust, said: "The unprecedented pressures created by the current heatwave, combined with the failure of a number of our chiller units, have led to significant disruption across several of our services."

Norfolk and Norwich University Hospitals NHS Foundation Trust also declared a critical incident after cooling systems affecting MRI scanners failed due to hot weather and humidity. The trust stated it had no working MRI scanners across its Norwich sites. Hundreds of patients had hospital appointments cancelled in Norfolk after the scanners stopped working. Radiotherapy machines and critical IT systems also stopped working in some NHS hospitals. Two linear accelerator machines used to treat cancer patients stopped working at one hospital due to high temperatures. Staff at one NHS trust were asked to turn off non-essential computers and electrical equipment, including lights, due to IT server overheating.

The London Ambulance Service recorded 642 category one calls on Wednesday, the highest number of life-threatening emergencies in its history for a single day. Category one incidents include cardiac arrests and patients who are not breathing. Hilary Williams, the clinical vice-president of the Royal College of Physicians, said: "There are reports of older patients arriving at hospital having collapsed or with dehydration." An unnamed doctor stated that older patients in one geriatric ward endured temperatures as high as 35C.

Hilary Williams said: "Buildings must be upgraded to withstand extreme heat and other climate risks." She added: "Hospitals should be places of safety, not settings where extreme heat puts patients and staff at risk." Williams also said: "It is not as simple as buying fans, which can present a fire risk when used alongside oxygen and may increase the spread of infection." The Department of Health and Social Care stated that all NHS trusts were required to have effective arrangements to deal with extreme heat.