When exposed to heat, the body activates several physiological mechanisms to maintain thermal homeostasis. However, these natural defenses are often overwhelmed in our modern cities. In an urban environment defined by heat-absorbing asphalt, concrete, and a lack of green spaces, these mechanisms become inefficient. If the surroundings are excessively hot, humid, or poorly ventilated—conditions amplified by the Urban Heat Island effect—the core body temperature begins to rise, and the risk of serious complications increases, ranging from cramps and exhaustion to potentially fatal heat strokes.
In recent years, the impact of this thermal stress has intensified, particularly in the dense urban centers of the Northern Hemisphere, which were historically less prepared for extreme temperatures. According to a study published in The Lancet eClinicalMedicine, between 2000 and 2019, there was an annual average of 489,000 deaths worldwide linked to extreme heat, highlighting the silent magnitude of this phenomenon. A recent analysis by Imperial College London estimated that during the European summer of 2025, two out of three heat-related deaths were a direct consequence of human-induced global warming — about 16,500 of the 24,400 recorded deaths. Both this and warnings from the World Health Organization reinforce the urgency of developing urban and architectural strategies capable of mitigating heat, protecting vulnerable populations, and reducing the growing burden of the climate crisis on public health.
