Cities are particularly miserable during heatwaves. With lots of concrete and asphalt surfaces, they soak up lots of heat and re-radiate it. Lots of tall buildings block cooling breezes. Factor in car exhaust and heat from air conditioners and it all adds up to the urban heat island effect. Cities can be several degrees warmer during the day and as much as 20 degrees warmer at night. All of this extra heat is not just a comfort issue, it is a serious health problem.
Particulate matter and toxic chemical pollutants are a pervasive problem in the air people breathe in many places. Poor air quality causes health problems worldwide and is a factor in diseases such as asthma, heart disease and lung disease.
