LUNGS, EXTREME HEAT, AND POLLUTION: THE NEW RESPIRATORY EMERGENCY OF SUMMER

In recent years, climate change has ceased to be merely an environmental issue and has become an increasingly central concern for respiratory medicine as well. Extreme heat waves, wildfires, and the increase in air pollution are directly altering the risk of lung disease.

The summer of 2026 is confirming a trend already evident in recent years: higher temperatures, greater formation of tropospheric ozone, and an increase in fine particulate matter are causing a rise in respiratory exacerbations, especially in vulnerable individuals.

Extreme heat as a respiratory factor

High temperatures not only affect general well-being but also have specific effects on the respiratory system.

Intense heat can in fact:
• increase respiratory rate
• worsen dehydration of the bronchial mucosa
• increase oxidative stress
• promote airway inflammation.

In patients with: • COPD • asthma • pulmonary fibrosis • chronic respiratory failure, these effects can result in significant clinical worsening.

The role of ozone
One of the most important aspects concerns tropospheric ozone (O₃). During very hot and sunny days, photochemical reactions between: • nitrogen oxides • volatile organic compounds • solar radiation lead to the formation of high concentrations of ozone. Ozone is a powerful respiratory irritant and can cause: • bronchoconstriction • increased bronchial inflammation • worsening of lung function • increased exacerbations of asthma and COPD.

Wildfires and PM2.5
Climate change is also increasing the frequency and intensity of wildfires. Smoke from wildfires contains high concentrations of: • PM2.5 • ultrafine particles • toxic organic compounds.

These particles penetrate deeply into the alveoli and are associated with: • increased respiratory hospitalizations • higher mortality • worsening of chronic diseases. In many European areas, wildfire smoke is becoming a new form of chronic exposure. The most vulnerable populations The effects of heat and pollution are not the same for everyone. The groups most at risk include: • elderly people • children • patients with chronic respiratory diseases • individuals with cardiovascular diseases • outdoor workers. In these patients, even small increases in pollution can lead to significant clinical consequences. A new paradigm: the lung as a 'climate organ' The most recent evidence suggests that the lung is one of the organs most sensitive to environmental changes. For this reason, a new concept is emerging: respiratory health as a direct indicator of environmental health.

Modern pulmonology must therefore integrate: • clinical medicine • epidemiology • environmental sciences • climate prevention. Implications for clinical practice This scenario requires some important changes. Patient education Patients must be informed about: • air quality • risk from heat waves • environmental protection strategies. Environmental monitoring The assessment of environmental exposure should increasingly enter daily clinical practice. Prevention Reducing air pollution represents one of the most effective strategies to decrease the burden of respiratory diseases. For many years climate change was perceived as a 'future' problem. Today it is a daily clinical reality. Heat waves and pollution are already altering epidemiology, exacerbations, and respiratory mortality. Respiratory medicine will increasingly have to confront these environmental factors, integrating them into prevention and in clinical management. The relationship between climate change and respiratory health is now evident. Extreme heat, ozone, fires, and particulate matter are transforming global respiratory risk. The pneumology of the future will inevitably also be an environmental medicine, capable of understanding how the climatic context directly influences the lung.