Heat and health

Rising ambient temperatures and the increasing frequency, duration, and intensity of heatwaves represent some of the most immediate and harmful impacts of global climate change. Far from being a mere seasonal discomfort, extreme heat is a significant physiological hazard that acts as a primary driver of climate-attributable morbidity and mortality worldwide.

As greenhouse gas emissions continue to alter our climate system, extreme heat events are breaking historical records with greater regularity. Compounding this challenge, the rapid expansion of urban environments creates "heat islands" that trap thermal radiation, leaving dense populations exposed to prolonged daytime heat and elevated nighttime temperatures without adequate recovery windows.

Working with partners across the health and climate research community, we're helping to map the complex pathways through which thermal stress compromises human health . When the human body is exposed to extreme temperatures, its core thermoregulatory mechanisms are pushed to their limits. This places strain on the cardiovascular and renal systems as the body works to dissipate heat. Our work focuses on quantifying how excess heat impacts health outcomes, across a range of critical focus areas:

• Excess mortality and hospital burden – Estimating the global, national, and localised mortality burdens associated with daily temperature fluctuations, sudden heatwaves, and prolonged cold spells.
• Cardiovascular and renal stress – Investigating the association between heat and heat stress, particularly among older populations, outdoor workers, and individuals with pre-existing chronic conditions.
• Socioeconomic vulnerability – Analysing how heatwave-attributable health burdens vary across different socioeconomic quintiles, identifying disproportionately affected neighbourhoods, and uncovering the intersecting systemic vulnerabilities (such as housing quality and access to cooling) that drive these disparities.