A new study reveals that extreme heat, particularly at night, is significantly driving up asthma-related emergency department visits in Baltimore-affecting both adults and children.
Researchers analyzed 819 adult and 695 pediatric asthma cases from 2016 to 2022, using geocoded health records alongside high-resolution temperature data. The strongest links emerged when they examined nighttime heat wave conditions, especially in socially vulnerable neighborhoods.
Baltimore's urban heat island effect prevents temperatures from cooling at night, and the findings highlight that traditional heat alerts-like the city's Code Red system-may miss these localized risks. The study tested 11 different heat wave definitions and found that nighttime minimum temperature metrics were the most sensitive indicators of asthma exacerbations.
The results underscore the need for public health systems to integrate granular temperature data and nighttime heat measures to better predict and respond to asthma risks.