Heat Waves and Hospitals: Building Healthcare Facilities That Survive Extreme Heat (Part 3.2)

This article is the fourth in GBCE's Extreme Heat series. In Part 1, we explored why extreme heat is becoming a long-term climate reality and an emerging risk for the building sector. In Part 2, we examined how cities and developers can respond through climate-responsive urban planning and building design. In Part 3.1, we looked at how residential buildings must adapt to protect occupants from rising temperatures. This article turns to healthcare facilities and why hospitals require an even higher level of resilience to protect patients, staff and critical services during prolonged heat events.

Series overview

• Part 1: Until The Next Heat Wave

• Part 2: Can Our Cities Survive the Next Heat Wave?

• Part 3.1: Heat Waves and Residential Buildings: Protecting Homes and Occupants

• Part 3.2: Heat Waves and Hospitals: Designing for Continuous Care Under Extreme Conditions

When the Building That Saves Lives Cannot Withstand the Heat

One in twelve hospitals worldwide, including one in sixteen in the United States, is projected to face a high risk of partial or total shutdown from extreme weather events by the end of the century. For a hospital, an extreme heat event is not simply a comfort issue. It is an operational stress test that arrives at the exact moment patient demand is highest. [Healthcare Design Magazine]

Unlike most other building types, hospitals cannot close, evacuate or pause operations when conditions become unsafe. They must continue to admit patients, run surgeries and sustain critical care, regardless of how extreme conditions outside or inside the building become. That requirement changes what resilient design means for healthcare facilities.

Hospitals Face a Different Kind of Heat Risk

Hospitals generate substantial internal heat loads of their own. Continuous occupancy, dense medical equipment, sterilisation processes and twenty-four hour lighting all add heat that has nothing to do with the weather outside. When extreme heat is layered on top of these internal loads, cooling systems come under sustained stress precisely when patient volumes and clinical demands are also rising. [CCR-Mag]

Heat waves also expose a gap in how many hospitals plan for power resilience. Emergency generators are typically sized to keep life-safety systems and clinical equipment running, not to sustain full chilled water, air movement and humidity control across the whole facility. A hospital can therefore have power for its ventilators while still losing control of indoor temperature during an extended outage. [ACHR News]

These are not hypothetical scenarios. During a record-breaking heat wave in California, backup generators failed at a major hospital, forcing staff to hand-ventilate intensive care patients while an evacuation was organised. [Fierce Healthcare]

Why Heat Resilience in Healthcare Is a Patient Safety Issue

Hospital patients are, by definition, a concentrated population of people who are least able to tolerate heat stress. Older adults, infants, people with chronic illness and those recovering from surgery or acute illness are all less able to regulate body temperature, which means the margin for error on indoor conditions is far smaller than in a typical building.

Extreme heat also threatens the supply chain that clinical care depends on. Vaccines, insulin and many other medications must be kept within narrow temperature ranges, and prolonged heat exposure or a cooling failure can compromise their effectiveness. Preparedness plans increasingly call for temperature-sensitive medical supplies to be integrated directly into a facility's heat response planning, rather than treated as a secondary concern. [U.S. Climate Resilience Toolkit]

Power loss compounds all of this. Ventilators, infusion pumps and cardiac monitors can fail within minutes of losing power, and intensive care and neonatal units are especially exposed because their patients have little physiological reserve to draw on during a disruption. [Medica Trade Fair]

Designing Hospitals That Stay Cool and Operational

Resilient healthcare design starts with the same passive principles that apply to any building: orientation, shading, insulation and high-performance glazing to reduce solar heat gain before mechanical systems are asked to compensate. In a hospital, however, these measures need to be paired with a higher standard of redundancy across every system the building depends on.

Cooling and power infrastructure should be sized and distributed so that chilled water, air movement and humidity control can be sustained across critical wards, not only life-safety circuits, during an extended grid disruption. Integrated planning across chillers, generators and distribution pathways closes the gap that many facilities discover only after a system fails under stress. [ACHR News]

As with residential and commercial buildings, hospitals should be assessed against future climate projections rather than historical weather data, since the facilities being designed today will need to remain operational through summers far hotter than those the original engineering assumptions were built around. [Scientific Data / PMC]

Retrofitting Existing Hospitals for Extreme Heat

Most hospitals that will be serving communities in 2050 have already been built, making retrofit a critical component of climate adaptation. While new healthcare facilities can integrate heat resilience from the outset, existing hospitals often require targeted upgrades to remain safe and operational during prolonged heat events. 

Priority measures include improving roof and wall insulation, installing cool or reflective roofing materials, upgrading glazing and external shading to reduce solar heat gain, and enhancing natural ventilation in non-clinical spaces where appropriate. 

Mechanical cooling systems, chilled water plants and backup power infrastructure should also be assessed and upgraded to ensure critical departments can maintain safe temperatures during periods of extreme heat or grid disruption.

By combining passive improvements with resilient mechanical and electrical systems, hospitals can reduce cooling demand, improve patient and staff comfort, and strengthen their ability to provide uninterrupted care in a warming climate. 

Source: WHO – Climate Resilient and Environmentally Sustainable Health Care Facilities (health facility adaptation and resilience) 

New Build Case Study: Khoo Teck Puat Hospital, Singapore

Khoo Teck Puat Hospital in Singapore shows how passive design can be applied at the scale of a full acute-care facility in a tropical climate.

The hospital was designed around its site's prevailing winds, with ward towers oriented to capture natural airflow and aluminium sunshades and light shelves used to control solar heat gain. This approach reduced the facility's reliance on mechanical ventilation by approximately sixty percent, while sunken courtyards and extensive greenery bring daylight and cooling into the lower levels of the building. [Living Future]

The result is a hospital that treats natural ventilation, shading and greenery as core infrastructure rather than aesthetic additions, lowering energy demand while creating a calmer, cooler environment for patients, staff and visitors. [gb&d Magazine]

What Healthcare Developers and Operators Should Do Now

Extreme heat preparedness in healthcare can no longer sit solely within emergency management plans. It needs to be built into the facility itself. Developers and operators should prioritise five actions.

●       Design cooling and power redundancy for full-facility operation, not only life-safety circuits.

●       Apply passive design, orientation and shading to reduce baseline cooling demand before adding mechanical capacity.

●       Integrate temperature-sensitive medical supply storage into heat preparedness planning.

●       Evaluate facility resilience against future climate projections rather than historical weather data.

●       Build redundancy into chilled water, ventilation and power distribution across critical wards.

These measures protect patient safety during the events that matter most, while also reducing operational energy use and strengthening the long-term resilience of healthcare assets as climate conditions continue to change.

Looking Ahead

Hospitals occupy a different category of risk than most buildings. They are expected to keep functioning precisely when conditions are at their most extreme, for patients who have the least capacity to tolerate failure.

Designing healthcare facilities for a hotter climate is not an optional upgrade. It is a direct extension of the duty of care that defines the sector.

Read the Whole Series

• Part 1: Until The Next Heat Wave

• Part 2: Can Our Cities Survive the Next Heat Wave?

• Part 3.1: Heat Waves and Residential Buildings: Protecting Homes and Occupants

• Part 3.2: Heat Waves and Hospitals: Designing for Continuous Care Under Extreme Conditions

SOURCES

1. Constructing Climate-Resilient Hospitals: 6 Strategies for Healthcare Facilities, Healthcare Design Magazine — https://healthcaredesignmagazine.com/trends/constructing-climate-resilient-hospitals-6-strategies-for-healthcare-facilities/163512/

2. Designing Resilient Healthcare Facilities in an Era of Climate Uncertainty, CCR-Mag — https://ccr-mag.com/designing-resilient-healthcare-facilities-in-an-era-of-climate-uncertainty/

3. Designing Critical Facilities for a More Volatile Grid, ACHR News — https://www.achrnews.com/articles/166409-designing-critical-facilities-for-a-more-volatile-grid

4. Backup generators fail at San Jose hospital during blackouts, Fierce Healthcare — https://www.fiercehealthcare.com/providers/backup-generators-fail-northern-california-hospital-during-record-breaking-heatwave

5. Impact of Extreme Heat on Health Care Facilities, U.S. Climate Resilience Toolkit — https://toolkit.climate.gov/sites/default/files/Hazard_Extreme_Heat_3.0_0.pdf

6. Power security in hospitals: risks and emergency systems, Medica Trade Fair — https://www.medica-tradefair.com/en/media-news/spheres-of-medica-magazine/medtech-devices/power-security-hospitals

7. Typical and extreme weather datasets for studying the resilience of buildings to climate change and heatwaves, Scientific Data / PMC — https://pmc.ncbi.nlm.nih.gov/articles/PMC11116384/

8. Khoo Teck Puat Hospital, Living Future — https://living-future.org/case-studies/award-winner-khoo-teck-puat-hospital/

9. Biophilic Design is King at This Singapore Hospital, gb&d Magazine — https://gbdmagazine.com/singapore-hospital/