Extreme Heat Puts Extra Pressure on NHS Hospitals as Equipment Fails and Demand Rises

Several NHS hospitals across England have declared critical incidents as the UK’s record-breaking June heatwave places increasing pressure on already stretched healthcare services.

The extreme temperatures have affected both patient care and hospital infrastructure, with some NHS organisations reporting failures to cooling systems, MRI scanners, radiotherapy equipment and IT systems. Rising demand for emergency care, particularly from people experiencing heat-related illness, has added further pressure.

Among the hospitals and NHS organisations affected are:

• Queen Alexandra Hospital, Portsmouth – Declared a critical incident after extreme heat caused failures to cooling systems affecting clinical areas, digital systems and other essential infrastructure. The hospital asked the public to attend only in genuine emergencies while engineers worked to restore services.
• University Hospital Southampton NHS Foundation Trust – Declared a critical incident as demand for emergency care increased significantly during the heatwave, with some non-urgent procedures postponed.
• Royal Devon and Exeter Hospital – Reported disruption after MRI scanners and other equipment were affected by the high temperatures, leading to the cancellation of hundreds of outpatient appointments.
• Norfolk and Norwich University Hospital – Declared a critical incident after cooling failures affected diagnostic equipment and hospital systems, resulting in the postponement of outpatient appointments.
• East Surrey Hospital – Earlier in the week, the hospital declared a critical incident due to exceptional demand associated with the heatwave, with emergency services prioritised for the most seriously ill patients.

The challenges extend beyond individual hospitals. Ambulance services have also reported increased demand, with the London Ambulance Service recording its busiest day on record for life-threatening emergencies during the current spell of extreme heat.

Healthcare leaders say the impact highlights the growing challenge that rising temperatures pose for NHS infrastructure. Many hospital buildings were designed decades before prolonged periods of extreme heat became more common, and not all clinical areas have modern cooling systems.

Alongside infrastructure issues, frontline staff are continuing to care for patients in difficult conditions. Doctors have described wards becoming uncomfortably hot, making infection prevention more challenging and increasing the physical demands on staff already working under pressure.

Older people, babies, pregnant women and those living with long-term health conditions remain among those most at risk during periods of extreme heat. Health officials continue to advise people to stay hydrated, avoid prolonged exposure to the hottest part of the day where possible, check on vulnerable family members and neighbours, and seek medical advice if symptoms of heat exhaustion worsen or develop into heatstroke.

While NHS organisations have activated their heatwave response plans, this week’s events demonstrate how extreme weather is becoming an increasingly significant operational challenge for health services across the UK.