Difficult convalescence and more frequent complications for those who live in city areas with strong increases in heat: this must be taken into account in the discharge.
Among the usual questions to be asked to patients discharged after an operation it may be necessary to add: “Do you have air conditioning in your house?”. Excessive temperatures in urban heat islands are linked to a more difficult recovery following surgery. This is supported by research presented at the 2026 American College of Surgeons conference held in Washington.
Based on work on 700,000 patients, those living in urban areas with higher temperatures are at higher risk of not recovering adequately after surgery (and therefore, for example, needing to be readmitted to hospital). Another side effect of urban architecture unprepared to protect us from the climate crisis.
A threat to full recovery
According to the analysis, led by Ohio State University, above an urban heat island intensity threshold of 2.19°C – a metric that measures the temperature difference between urbanized and surrounding areas – each additional degree of heat is associated with an 8% greater chance of not achieving desired outcomes after an operation.
The “textbook” post-operative course considered in the study included the absence of complications, additional days of hospitalization, further hospitalizations after discharge and survival for at least 30 days after surgery.
These desirable conditions for each patient, however, are more difficult to achieve in urban heat islands, densely built areas in which land changes, human activities and the building materials used determine a gap in temperatures compared to the surrounding areas.
Lack of vegetation and natural soil, tall and close buildings, emissions from road traffic and domestic installations, and the abundance of concrete, asphalt and other heat-absorbing materials can lead to temperature differences between heat islands and external rural areas ranging from 0.5°C to 3°C for a medium-sized city.
Right to heal not equally distributed
The correlation between heat islands and the obstacle to recovery was more evident in areas with higher social and economic vulnerability, where the chances of not having domestic air conditioning or being in neighborhoods with an urban heat island effect are more marked.
Unfortunately, access to cooling is not guaranteed to everyone without distinction. Patients with low income, or those living in difficult housing conditions, elderly patients or patients with chronic pathologies or disabilities could be more affected by this effect.
The association between excess urban heat and poor convalescence is also stronger in patients returning from oncological operations, emergency procedures or at high risk of heart disease. The latter type of patient may have a lower tolerance to stress induced by dehydration and other alterations in water balance.
The recommendation: plan for discharge
For doctors, the results could be an invitation to organize patients’ discharges more carefully: asking, for example, if they have access to fans or air conditioners, if they know of cooled public spaces near their home, and if they have the possibility to stay hydrated, will serve to ensure that the conditions are in place for a correct recovery from an operation.
