The Queen Alexandra Hospital in Portsmouth, UK, has declared a critical incident.

The National Health Service (NHS) facility said that chillers had failed at its on-site data center, impacting digital services from Wednesday. Some planned care and appointments have been postponed, while those still traveling to the Queen Alexandra have been warned that “the hospital is very hot.”

The data center outage comes amid a heatwave in the UK, with temperatures topping 34°C (93.2°F). The record heat is due to a combination of a strong high-pressure system and anthropogenic climate change.

UK weather service the Met Office has issued an extreme heat red weather warning.

“The loss of cooling capacity has led to elevated temperatures in a number of areas across the Trust, affecting our digital systems and critical clinical services, including theatres, cardiac catheter laboratories (cath labs), and diagnostic scanning facilities,” the hospital said.

Mark Orchard, deputy CEO and CFO, Portsmouth Hospitals University NHS Trust, added: “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.

“Our teams are working hard to repair the affected equipment, restore systems safely, and ensure we continue to provide safe care for our patients.”

An outage at two London hospitals during the 2022 heatwave cost £1.4 million ($1.7m), an NHS review found.

Two data centers supporting the Guy’s and St Thomas’ NHS Foundation Trust hospitals collapsed amid that period of extreme heat.

There were more than 100 delays, and one patient was unable to receive an organ transplant, causing “moderate harm.” The issues also caused “fatigue, stress, and an adverse impact on morale” for staff.

It took six weeks for services to fully return.

Climate risk financial modeling firm First Street this month said that 79 percent of global data center capacity is facing “acute climate hazards,” with major hubs like Northern Virginia, Johor, and Marseille in the report’s highest climate-risk tier.