Thermometers Make the Case for Hospital Sustainability Amid Heatwaves

When the Thermometer Rises, So Does the Case for Hospital Sustainability: Europe’s Heatwave and the Green Team Opportunity

Two Heatwaves, One Summer, and a Clear Signal for Healthcare

‍

By June 2026 Ireland already had one official heatwave with Met Éireann confirming five consecutive days at or above 25°C in late June, and temperatures peaking at 32.1°C in Athenry. By July 2026, Met Éireann meteorologists had issued two commentaries on hot weather, with tropical night sand daytime temperatures set to climb to 30°C in parts of the country. Across Europe, the wider heat dome has been described as the most severe and widespread heatwave ever recorded on the continent. Denmark set an all time high of 37.0 °C in two locations, and France and Spain recorded their hottest days ever. World Meteorological Organization notes approximately 489,000 heat-related deaths annually, including those tragically killed in forest fires and as fires blazed in the Wicklow mountains. For those leading sustainability, estates or facilities within Irish healthcare, heat is no longer a summer inconvenience as the Irish climate becomes both warmer and wetter. It is a recurring operational and clinical risk, and the systems built to manage it - energy, cooling, water, procurement, waste, - are the same systems your carbon reduction plan is already trying to fix.

Why This Matters to Green Teams and Healthcare Sustainability Leads

‍

Heat stress has a direct clinical cost.  While there is little specific information for Ireland, France, Spain, Italy, and, Europe more generally, all show higher hospital admissions during a heatwave. For example, those with renal, metabolic, heat illness, and some respiratory and mental health diagnoses are at increased risk placing added pressure on emergency departments, as are very young children and older patients and those with chronic respiratory or cardiac conditions.

‍

Heat and energy resilience are now linked.  During the European heat dome, when hot weather settles in, there is typically less wind so wind-powered electricity generation reduces.  At other times up to 75% of Ireland’s electricity can come from renewables. When combined with soaring demand for AC in Britain and France, sourcing electricity through Ireland's inter-country interconnectors becomes challenged.  Under such circumstances the carbon footprint of scope 2, i.e. purchased electricity increases. Increased solar PC energy offers the potential to balance out the temporary reduction in wind energy and can be located on healthcare sites as is commonly seen on housing today. This indicates the importance of the all-island grid resilience and a reminder that hospital energy resilience (on-site renewables, battery storage, demand management) risks becoming a patient-safety issue, not just a cost line.

‍

The HSE already has the scaffolding in place. The HSE Climate Action and Sustainability Office runs a Climate Action Strategy 2023–2050, a Net-Zero Decarbonisation Roadmap, and a network of 16 Energy Officers supporting Significant Energy Users across the country, alongside the Green Healthcare Programme's water, waste and food-waste initiatives. Green teams are being resourced, not just requested. Hospitals and Regional Health Authorities have been actively recruiting sustainability and green team roles to help implement these strategies locally, a strong signal that estates-level climate action has moved from "nice to have" to core hospital function. Similarly, private sector hospitals globally are acting, perhaps aligned to the Joint Commission International's Accreditation Standards for Hospitals the 8th Edition of which introduced a Global Health Impact (GHI) chapter which integrates sustainability into the core governance and management of healthcare facilities.

Globally, healthcare is estimated to contribute around 5% of greenhouse gas emissions, and in developed countries like Ireland the figure can run as high as 10% of national totals. In 2024 the HSE in Ireland contributed 19% of the public sector energy consumed. During heatwaves cooling and related electricity demand adds directly to the footprint of a healthcare facility when unusually high temperature may already be making us grumpy.

‍

Practical Heatwave-Specific Actions with a Sustainability Payoff

• Audit your cooling before you need it. Identify wards, theatres, labs, offices and the server/plant rooms most exposed to overheating, and prioritise passive measures (external shading, blinds, night purging of heat) ahead of energy-hungry mechanical cooling.
• Where available use your Energy Officer, such as via HSE's Capital and Estates. If your site is one of the HSE's Significant Energy Users (SEUs) as identified through your organisations M&R SEAI reporting, your regional Energy Bureau contact may help model heatwave demand spikes and identify shallow retrofit projects that cut both peak load and annual carbon.
• Pressure-test backup power and demand flexibility. The European heatwave showed how quickly grid margins can tighten. Confirm generator fuel contracts, and explore demand-response participation so your site can flex non-critical load during system stress events.
• Consider on-site solar and other renewable energy source, particularly during capital and retrofit projects. For example Ireland has upwards of 100,000 microgeneration contributors to the national grid reducing dependence on fossils fuel.
• Protect vulnerable patients and staff with low-carbon comfort measures first. Fans, hydration stations, adjusted staffing patterns, and shaded and planted outdoor areas reduce heat-related admissions without the emissions cost of blanket air conditioning.
• Review your procurement criteria for heating and cooling equipment.  When new AC or portable cooling units are purchased under pressure, sustainability criteria are often the first thing dropped.  Build energy efficiency and low global warming potential (GWP) refrigerants specs into heat, ventilation and AC equipment requirements now, before the next hot spell. Make sure to include emergency procurements which helps smooth the path for your colleagues down the line.
• Track water use closely. Heatwaves increase both patient hydration needs and cooling-system water demand. The HSE's Water Efficiency Guide and sub-metering case studies from sites like Cork University Hospital and Connolly Hospital Blanchardstown offer a ready-made starting point.  
• Fold heat resilience into your Climate Action Roadmap. Rather than treating heatwave response as a standalone estates issue, connect it to your existing scope 1, 2 and 3 reporting, so investment in cooling resilience also counts toward your net-zero targets.
• Ask Cooling, HVAC And Consumables Suppliers for their carbon reduction plan. As approximately 80% of hospital emissions sits in scope 3, purchased goods, equipment and services, ask cooling, HVAC and consumables suppliers for their own carbon reduction plans as part of tender criteria, so heatwave preparedness doesn't quietly add to your supply chain carbon footprint.

The Bigger Healthcare Picture 

‍

Heatwaves put a spotlight on something sustainability leads already know: energy, water, procurement and clinical resilience are not separate workstreams, they are the same system viewed from different angles. As green teams across the HSE and private healthcare sector continue to evolve, the healthcare facilities that treat heatwave readiness as part of their carbon reduction plan, rather than a separate emergency response, will be better placed for the next one. And the one after that.

‍

 If your team is working to bring supply chain and estates emissions data together into one clear picture, Nocomed's platform is built specifically for healthcare and life sciences organisations navigating exactly this challenge.