Britain’s blistering heatwave has pushed parts of the National Health Service to breaking point, with hospitals forced to cancel hundreds of appointments, treat patients in corridors and declare critical incidents as soaring temperatures cripple vital equipment.
Doctors have warned that the extreme weather is exposing dangerous weaknesses in hospital infrastructure, with key medical machines — including MRI scanners — shutting down as temperatures continue to climb.
The intense heat has also triggered a sharp rise in emergency admissions, particularly among elderly patients struggling to cope with the conditions, prompting several NHS trusts to activate emergency measures.
The Norfolk and Norwich University Hospitals NHS Foundation Trust raised the alarm after MRI scanners stopped functioning due to the excessive heat.
As a result, the trust cancelled at least 362 outpatient appointments while prioritising inpatients and patients on suspected cancer two-week referral pathways.
MRI scanners, which allow doctors to examine the inside of the body and are frequently used to diagnose conditions such as brain tumours and serious injuries, are considered essential diagnostic tools.
Dr. Hillary Williams, Clinical Vice-President of the Royal College of Physicians, warned that hospitals risk becoming places where extreme heat threatens patients rather than protects them if urgent upgrades are not made.
“Patients are facing overcrowding, and there are issues with machines, laboratories and kidney dialysis — all fundamental to providing safe patient care,” she said.
Speaking to The Guardian, Dr. Williams added: “The impact of heatwaves cannot be overstated. There is a sense of foreboding when we see the weather forecast because we know what is to come, and there is very little staff can do.”
Hospitals in other parts of the country have reported similar difficulties.
In Portsmouth, Queen Alexandra Hospital declared a critical incident after failures in its cooling units caused elevated temperatures across the facility.
The breakdown led to significant disruption to several services, including operating theatres, diagnostic scanning facilities and cardiac laboratories.
Meanwhile, NHS Hampshire and Isle of Wight said the soaring temperatures had placed the region’s entire healthcare system under severe pressure.
The organisation said a critical alert issued this week by the U.K. Health Security Agency highlighted a risk to life, including for people who are normally healthy, prompting emergency steps to protect services.
The Royal Devon and Exeter Hospital also declared a critical incident on Thursday evening due to the widespread effects of extreme heat and humidity on both patients and staff.
The London Ambulance Service reported its busiest day ever for life-threatening emergencies, with crews responding to 642 category one calls on Wednesday alone.
The figure covers the most serious medical emergencies, including cardiac arrests and other life-threatening illnesses and injuries.
The incidents have underlined the strain extreme weather can place on hospital infrastructure, worsening pressures already caused by rising demand and staffing shortages.
Healthcare workers say both temperatures and tensions are increasing as staff struggle to maintain expected standards of care amid unprecedented conditions.
Resident doctors are now seeking guidance from specialist colleagues on how best to respond and are calling for the NHS to prepare more effectively for future heatwaves by providing additional support for frontline staff.
Dr. Williams said clinicians can take immediate steps to protect patients, including reviewing medications that affect hydration levels and ensuring medicines are stored correctly.
However, she stressed that those actions must be backed by wider reforms aimed at strengthening hospital infrastructure and improving resilience across the NHS.
Responding to the situation, the Department of Health and Social Care said all NHS trusts are expected to have plans in place to deal with periods of extreme heat.
A spokesperson said trusts were urgently coordinating responses to increased demand on health services while working to protect vulnerable patients.
