The heat and humidity have prompted Connecticut environmental officials to forecast unhealthy air quality for children and adults such as the elderly who have asthma and other respiratory illnesses.
The forecast is for Monday and Tuesday due to elevated ground-level ozone pollution for southern parts of Fairfield, Middlesex, New Haven and New London counties.
A forecast of "unhealthy for sensitive groups" indicates an increased likelihood of respiratory symptoms and breathing discomfort in children and adults with respiratory disease.
Unhealthy concentrations of ground-level ozone can cause or worsen respiratory problems and other health troubles.
Ground-level ozone occurs primarily during hot summer days. Strong sunshine causes chemical reactions of air pollutants from motor vehicles, power plants and industry and household activities, forming ozone.
Ground-level ozone and fine particulate matter pose health risks.