More than 1,000 NHS operations cancelled during UK’s record May and June heatwaves

# What the investigation found Carbon Brief sent freedom-of-information requests to 140 NHS trusts and health boards in England and Wales about operations cancelled during the record heatwaves in May and June 2026. Fifty-nine trusts supplied datasets detailing cancellations the trust attributed to the extreme heat. Those responses record 1,110 heat-related surgery cancellations across two 17-day periods: 22–28 May and 18–27 June.

Not all trusts track heat as a reason for cancellation. Sixty-three trusts responded without providing heat-related details, often saying they do not routinely record that information. Because of this gap, the disclosed total should be treated as a conservative lower bound.

# Types of surgeries affected Most cancelled procedures were elective, scheduled in advance. Among the 596 cancellations with procedure-level details, the largest single category was orthopaedic operations: 167 cancellations (for procedures such as hip and knee replacements). Eye, gynaecological and urological surgeries were also commonly cancelled, reflecting how frequently those procedures are scheduled.

The dataset also includes higher-risk cases: at least eight heart operations and seven skin-cancer removals were cancelled. The investigation found at least 10 emergency operations — defined as for life-threatening conditions — were cancelled due to heat, and 18 surgeries were abandoned partway through because theatres became intolerably hot or systems failed.

# Where cancellations were concentrated Southern England saw many of the cancellations, corresponding to the highest recorded temperatures during the heatwaves. Surrey and Sussex Healthcare NHS Trust reported the most cancellations: 140, all at Crawley Hospital. Other local hotspots included south Essex, parts of London, Dudley in the West Midlands and areas of south Wales.

Among trusts that provided complete datasets for the period, roughly 7% of all surgery cancellations were recorded as heat-related. Carbon Brief frames that figure alongside other pressures the NHS already faces — staffing shortages, long waiting lists and limited bed capacity — to show how heat adds further operational strain.

# Why heat causes cancellations

Dr Dmitri Nepogodiev, a public health surgery researcher at the University of Birmingham, told Carbon Brief that hospitals will prioritise urgent cases but added: "Behind all of these statistics…are real people who have probably already been waiting a long time." Richard Egan, an endocrine surgeon and national clinical director within NHS Wales, warned: "That's a significant impact on waiting lists…For every week that patients are waiting on a waiting list, their condition could get worse and deteriorate."

# What this reveals for NHS planning The investigation exposes a gap in routine recording of climate-related disruption within many trusts. The disclosed cancellations demonstrate how extreme heat can directly disrupt surgical services, including emergencies. Trust-level hotspots match the areas of highest temperatures in the recorded heatwaves.

The data should inform local and national decisions about adapting hospital infrastructure and operational protocols for high temperatures. Short-term responses (cooling measures, scheduling changes) and longer-term infrastructure upgrades (ventilation, climate control in theatres and wards) are implied by the pattern of cancellations, though the FOI dataset itself does not document specific mitigation actions.

# Bottom line The Carbon Brief FOI investigation provides an unprecedented, if incomplete, snapshot: at least 1,110 NHS operations were cancelled because of the May and June 2026 heatwaves. Because many trusts do not track heat as a cause for cancellation, the number is likely higher, and the cancellations included both routine and critical procedures.