During a heatwave, official weather stations might record a similar baseline temperature for an entire area, but the actual physiological impact and local temperatures vary enormously from street to street.
The environment we live in is a key determinant of our health—a premise that is one of the core scientific pillars of the Girostudi project. While extreme temperatures put the human body to the test, how we respond to this heat stress depends heavily on our surroundings.
This relationship between our environment and our well-being is captured by the concept of the exposome: the totality of environmental, social, and lifestyle factors that surround us from childhood and ultimately shape our biology.
The “Urban Heat Island” effect
The materials that dominate our cities, such as asphalt and concrete, have high thermal inertia—meaning they absorb and retain a large amount of solar radiation during the day. At night, as the air cools, these surfaces slowly release this trapped heat, acting like radiators and preventing temperatures from dropping. This phenomenon is known as the Urban Heat Island (UHI) effect, creating stifling microclimates in built-up areas.
The role of vegetation
In contrast, areas with abundant trees and green spaces act as natural temperature regulators. Beyond providing shade, plants actively cool the air through evapotranspiration: they release water vapour that absorbs heat from the surrounding environment to evaporate—an endothermic process that works just like a natural air conditioner.
The impact on our bodies and sleep
Exposure to high temperatures triggers natural defence mechanisms to prevent heatstroke. The brain signals peripheral vasodilation (diverting blood flow to the skin to radiate heat away from the body) and activates sweating to cool us down through evaporation. All of this forces the cardiovascular system to work much harder.
This effort becomes critical during sweltering nights. For the brain to trigger and maintain deep sleep, our core body temperature needs to drop by approximately one degree. If the environment remains too warm at night, this natural cooling process fails, disrupting sleep. Chronic poor sleep is a silent risk factor for cardiovascular and metabolic health.
A wider perspective on health
Understanding population health means looking beyond genetics and individual habits. Urban design, housing quality, and socioeconomic factors are key determinants of our physical well-being. This is why research projects like Girostudi take a multidimensional, long-term approach to data collection. Only by understanding how our exposome interacts with our physiology can we design healthier cities and more effective preventive health strategies.
The key piece of the puzzle is you
However, all of this top-tier scientific research requires a human driving force. Girostudi can only move forward with the active involvement of our community. Being randomly selected to participate is far more than a statistical data point; it is a vital contribution. It means your daily routines, your voice, and your biology will represent thousands of other residents in your town and across the entire Girona region.
Taking part is a powerful commitment to our region and to future generations. If you receive a letter or a call from Girostudi, remember that your response is invaluable.
Say yes and help us shape the future of our region’s health, rooted in our community and a shared sense of belonging.
