NHS England Heatwave IT Failures: How Extreme Heat Disrupted Hospitals and Patient Care

When temperatures in parts of the UK exceeded 40°C for the first time on record, NHS hospitals faced an unexpected challenge. It wasn’t just the surge in heat-related illnesses that stretched services. The heat itself began breaking the technology that keeps hospitals running.

Reports of NHS England heatwave IT failures emerged as cooling systems struggled, servers crashed, and sensitive medical equipment became unusable. For patients, this meant cancelled appointments, delayed procedures and, in some cases, being diverted to other hospitals.

This article explains what happened during the heatwave, why NHS digital systems proved vulnerable to extreme temperatures, and what is being done to prevent a repeat during future UK heatwaves.

What Happened During the NHS England Heatwave IT Failures?

July 2022 saw the UK record its highest ever temperature. Coningsby in Lincolnshire reached 40.3°C. For context, the previous record stood at 38.7°C, set just three years earlier. This wasn’t just hot by British standards, it was hotter than parts of the Sahara Desert on the same day.

The NHS was already under immense pressure. Ambulance services had declared critical incidents days before the peak. But something else was going wrong inside hospital buildings that few had anticipated.

Which NHS Hospitals Were Affected?

Several NHS trusts reported significant IT problems. The most widely reported failures occurred at:

• Hillingdon Hospitals NHS Foundation Trust – saw computer systems crash, leading to cancelled outpatient appointments and disruption to radiology services
• Royal Berkshire NHS Foundation Trust – reported network failures that affected multiple systems
• St George’s University Hospitals NHS Foundation Trust – experienced issues with clinical systems

Other trusts, including Nottingham University Hospitals and Leeds Teaching Hospitals, also reported IT disruptions, though on a smaller scale.

What became clear was that the problem wasn’t isolated to a single region or type of hospital. It affected modern and older buildings alike.

What Systems Failed?

The failures weren’t limited to one type of technology. Several critical systems were compromised:

• Network infrastructure – In some hospitals, entire networks went down, meaning staff couldn’t access emails, internal systems or the internet.
• Electronic patient records – Systems like the Electronic Patient Record (EPR) became inaccessible in affected hospitals. This meant clinical staff couldn’t view medical histories, medication lists or test results.
• Diagnostic equipment – MRI scanners and radiotherapy machines are particularly sensitive to temperature and humidity. Some stopped working entirely. Others were shut down preemptively to prevent permanent damage.
• Telephone and communication systems – Some trusts reported failures in internal phone networks, making it harder for staff to coordinate care.
• Air conditioning and cooling – The irony wasn’t lost on anyone: the very systems designed to protect equipment from heat were struggling to keep up.

Why Did Extreme Heat Cause IT Failures in NHS Hospitals?

Understanding why the NHS England heatwave IT failures occurred requires looking at the infrastructure. Many hospital buildings simply weren’t designed for this kind of heat.

How High Temperatures Affect Data Centres

Data centres are the backbone of modern healthcare. They store patient records, diagnostic images and the clinical systems that staff rely on.

These facilities are packed with servers that generate substantial heat during normal operation. In ideal conditions, they need to be kept between 18°C and 27°C. When ambient temperatures pushed above 40°C, air conditioning systems in some trusts couldn’t maintain safe operating temperatures.

Servers began overheating. Some shut themselves down to prevent permanent hardware damage. Others started malfunctioning. This created a cascade effect: one failed server can cause network instability, affecting other connected systems.

Cooling System Limitations

The UK has traditionally had a temperate climate. Hospital cooling systems were designed with this in mind. They could cope with the occasional hot day, but not prolonged heat waves.

Some trusts rely on air conditioning units that simply aren’t powerful enough for extended 40°C temperatures. Others use cooling systems that require water—an increasingly precious resource during heatwaves when supply can be strained.

In the 2022 heatwave, many cooling systems were running at maximum capacity and still couldn’t keep equipment within safe limits. Some trusts had to make the difficult decision to power down certain IT systems to prevent permanent damage.

Medical Equipment Sensitive to Heat

MRI machines use superconducting magnets that require precise temperature control. Heat can affect the liquid helium used to cool these magnets, potentially causing them to quench—a process where the magnet stops superconducting, which can be expensive and time-consuming to fix.

Radiotherapy equipment is similarly sensitive. Linear accelerators used in cancer treatment rely on complex electronics and cooling systems. If temperatures climb too high, these machines become unreliable or unusable.

There were reports of NHS England hospitals having to cancel radiotherapy appointments because equipment couldn’t be safely operated.

Infrastructure Challenges Facing Older Hospitals

This is perhaps the most concerning aspect of the NHS England heatwave IT failures. Many NHS buildings date back to the post-war era. Some use infrastructure that’s even older.

These buildings weren’t designed for 40°C heat. They weren’t designed for the level of technology that modern healthcare relies on. Retrofitting these buildings is possible but hugely expensive.

Even relatively modern hospitals faced problems. This suggests it’s not just the age of buildings causing issues—it’s that the frequency and severity of extreme heat events are outpacing the assumptions that informed hospital design.

How Did the IT Failures Affect Patient Care?

The technology failures during the heatwave weren’t just an inconvenience for hospital IT departments. They directly affected patients.

Appointment Delays

NHS hospitals were forced to cancel or delay thousands of appointments. At Hillingdon Hospital alone, more than 400 outpatient appointments were cancelled over several days. These weren’t just routine checkups they included diagnostic scans and follow-ups for existing conditions.

Cancelled Procedures

Some elective surgeries were postponed because patient records weren’t accessible or because diagnostic scans couldn’t be performed. While hospitals prioritised emergency and cancer care, many patients waiting for treatment were left in limbo.

Emergency Services

Emergency departments remained open, but the IT failures created additional pressures. When systems go down, staff must revert to paper-based processes. This is slower and increases the risk of errors.

Ambulance services were also affected. Some experienced delays in handover times because hospitals couldn’t process patients quickly enough.

Impact on NHS Staff

The pressure on staff during the heatwave was immense. They were dealing with an increase in patients presenting with heat-related conditions while simultaneously struggling with systems they’d relied on for years.

NHS staff had to make rapid decisions in difficult circumstances. They worked in overheated wards while trying to keep patients cool. And they had to manage the transition to manual processes when digital systems failed.

Patient Safety Concerns

This is where things get more serious. When electronic patient records are unavailable, clinicians may not have access to:

• Medication histories
• Allergy information
• Recent test results
• Clinical notes from previous visits

While most trusts had backup procedures, these were slower and more cumbersome. There were concerns about increased risk of medication errors and the potential for duplicate tests being ordered.

Which NHS Services Were Most Affected?

Some NHS services were more vulnerable to the heatwave IT failures than others.

Diagnostic Imaging

MRI, CT and PET scanners were among the hardest hit. These machines generate significant heat themselves and are sensitive to ambient temperatures. Some trusts reported having to shut down scanning equipment for hours at a time.

Cancer Treatment

Radiotherapy services faced particular challenges. Linear accelerators used to treat cancer are among the most sensitive pieces of equipment in hospitals. Some trusts had to postpone treatments or offer patients slots at alternative facilities.

Digital Patient Records

EPR systems were inaccessible in several hospitals. This affected every aspect of care—from emergency admissions to outpatient clinics. Some trusts reported that parts of their EPR systems were offline for more than 24 hours.

Emergency Departments

A&E departments felt the strain from multiple angles. An increase in heat-related attendances coincided with IT failures that slowed down admission and discharge processes.

What Is the NHS Doing to Prevent Future Heatwave IT Failures?

Learning from the NHS England heatwave IT failures is now a priority. Several initiatives are underway.

Improving Cooling Infrastructure

NHS England has published guidance on managing heat risks in healthcare settings. This includes recommendations for:

• Auditing existing cooling capacity
• Upgrading or replacing inadequate systems
• Installing portable cooling units for critical areas
• Improving building insulation and ventilation

Some trusts are now implementing more robust cooling solutions for their data centres and equipment rooms.

Upgrading Digital Systems

The NHS has been moving toward more resilient digital infrastructure, though progress is slow. Key priorities include:

• Improving backup power and cooling for critical IT systems
• Ensuring electronic patient records can operate during network outages
• Exploring cloud-based solutions with better resilience to physical disruptions

The NHS Digital Transformation programme includes efforts to modernise IT infrastructure across the health service.

Emergency Response Planning

Trusts are now expected to have specific plans for managing heat-related IT failures. This includes:

• Clear escalation procedures
• Backup processes for critical clinical systems
• Communication plans for patients whose appointments are affected

Some trusts have started running heatwave simulation exercises to test their preparedness.

Climate Adaptation Strategies

The NHS is increasingly recognised as being vulnerable to climate change. NHS England has set a target to become net zero by 2040, but adaptation is equally important.

At a national level, the NHS is working with the UK Health Security Agency (UKHSA) to develop comprehensive heatwave response plans that address technology failures alongside clinical pressures.

What Should Patients Do During NHS Heatwave Disruptions?

If future heatwaves cause NHS service disruptions, there are steps patients can take to stay informed and protected.

Check Your Appointment

If you have a scheduled hospital appointment, check online or call the hospital before travelling. Trusts typically update their websites and social media channels with disruption information.

During the July 2022 heatwave, many patients arrived at hospitals only to find their appointments had been cancelled. NHS trusts are working to improve communication, but it’s still worth confirming before you travel.

Use NHS Online Services

The NHS App and NHS website offer a range of services that don’t depend on hospital IT systems. You can:

• Check symptoms
• Order repeat prescriptions
• Find NHS services near you
• Access some test results

While these services weren’t always directly affected, they remained a useful alternative for some patients during the heatwave.

Know When to Seek Urgent Care

Heat-related illness can be serious. Know the signs of heat exhaustion and heatstroke. If you or someone else experiences:

• Confusion or disorientation
• Hot, dry skin with no sweating
• A high temperature (above 39°C)
• Breathing difficulties

This is a medical emergency. Call 999 or visit your nearest A&E.

Be Patient With NHS Staff

During heatwave disruptions, NHS staff are under enormous pressure. They’re working in difficult conditions to maintain patient care. A little patience goes a long way.

Could Climate Change Increase Future NHS Disruptions?

The NHS England heatwave IT failures of July 2022 are unlikely to be a one-off event.

The UK’s climate is changing. The Met Office has confirmed that the record-breaking temperatures seen in 2022 are a sign of things to come. By 2050, temperatures above 40°C could be expected every three to four years, even under moderate emission scenarios.

This means the pressure on NHS infrastructure will only increase.

Rising UK Temperatures

The UK’s average summer temperature has risen by about 1°C since the 1960s. That might sound small, but it translates into a significant increase in extreme heat events. The chances of exceeding 40°C are now about ten times higher than they were in the pre-industrial era.

Increasing Pressure on Healthcare Infrastructure

Hospitals will face more frequent heatwaves, each one potentially causing similar IT failures. The NHS needs to invest not just in reactive fixes but in fundamentally resilient infrastructure.

Future Planning

The Department of Health and Social Care has acknowledged the need for better climate resilience across the healthcare sector. This includes:

• Building new hospitals to higher environmental standards
• Retrofitting existing buildings with better cooling and insulation
• Designing digital systems that can withstand higher temperatures

These changes will take time and significant investment.

Hospital Resilience

Building hospital resilience is about more than just cooling systems. It includes:

• Ensuring backup power and cooling for critical IT
• Building redundancy into digital systems
• Training staff to respond to technology failures
• Strengthening supply chains for equipment vulnerable to heat

Hospitals are also working to reduce their own environmental impact, which helps mitigate the wider problem.

Lessons Learned From the NHS England Heatwave IT Failures

The NHS England heatwave IT failures exposed vulnerabilities that had existed for years but had never been tested to this degree.

Infrastructure Investment

The NHS estate is vast—there are more than 1,200 hospitals in England alone. Many were built in an era when air conditioning was a luxury, not a necessity.

Investment in infrastructure needs to accelerate. This isn’t just about patient comfort. It’s about keeping essential services running during extreme weather events.

Digital Resilience

The NHS’s digital transformation has created huge benefits for patient care. But the heatwave showed that new systems also create new vulnerabilities.

Building digital resilience means designing systems that can operate under extreme conditions. This includes:

• Ensuring data centres can stay cool during heatwaves
• Building redundancy into critical systems
• Maintaining robust backup processes

Modernising Hospitals

The NHS has a capital investment programme that includes building new hospitals and upgrading existing facilities. Climate resilience needs to be at the heart of these projects.

This isn’t just about technology. It’s about design, location, and how buildings interact with their environment.

Preparing for Hotter Summers

NHS leaders have acknowledged that they need to prepare for hotter summers, not as an anomaly but as the new normal.

The NHS’s own Sustainable Development Unit has been working on climate adaptation plans for several years. But the speed of change is accelerating—and so must the response.

Frequently Asked Questions

What caused the NHS England heatwave IT failures?

Extreme temperatures exceeding 40°C in some areas—caused hospital cooling systems to struggle, leading to server overheating and IT failures.

Which hospitals were affected?

Trusts including Hillingdon Hospitals, Royal Berkshire and St George’s University Hospitals reported significant issues. Other NHS trusts also experienced disruption during the heatwave.

Were emergency services affected?

Emergency departments remained open, but delays in patient processing affected ambulance handover times in some locations.

What should patients do if their appointment is delayed?

Check your hospital’s website or contact the hospital before travelling. Where appropriate, use NHS online services and allow extra time, as staff may be managing significant operational pressures.

Can heat damage hospital IT systems?

Yes. Servers and other electronic systems are sensitive to high temperatures. Extreme heat can also affect specialist medical equipment, including MRI scanners and radiotherapy machines.

Is the NHS preparing for future heatwaves?

Yes. NHS England and individual trusts are investing in improved cooling infrastructure, upgrading digital systems and strengthening heatwave response plans to improve resilience.

How does climate change affect hospitals?

More frequent periods of extreme heat place additional pressure on hospital buildings, digital infrastructure and medical equipment, making long-term climate resilience increasingly important.

Did the heatwave affect cancer treatment?

Yes. Some radiotherapy services experienced disruption because temperature-sensitive linear accelerators had to be shut down temporarily to prevent equipment damage.

How did IT failures affect patient safety?

When electronic patient records became harder to access, clinicians faced delays retrieving medication histories and test results, increasing the risk of slower decision-making and treatment delays.

What are NHS hospitals doing to prevent future heatwave IT failures?

Hospitals are improving cooling systems, modernising digital infrastructure, increasing server resilience and developing comprehensive heatwave response plans to reduce the risk of future disruptions.

Conclusion

The NHS England heatwave IT failures of July 2022 provided a stark warning. The health service has built its digital capabilities over decades, but many of those systems are vulnerable to the temperatures we can now expect to see more regularly.

Patients bore the brunt: cancelled appointments, delayed procedures and, in some cases, anxiety about whether treatment would go ahead.

The NHS is already taking steps to improve resilience, from cooling infrastructure to digital system upgrades. But the scale of the challenge shouldn’t be underestimated. Many hospitals were built in a different climate era. Retrofitting them for what’s coming will require sustained investment.

Extreme heat is becoming the new normal. The NHS will need to adapt. And while the NHS is working on that adaptation, patients can prepare by staying informed and knowing what to do when the next heatwave hits. Follow UKHealthInsight for more interesting guides!