Extreme temperature and humidity exposure elevates acute intracerebral hemorrhage risk

This study examines the association between extreme temperature, relative humidity, and acute intracerebral hemorrhage (ICH) risk using a time-stratified case-crossover design. Data from 2,284 ICH patients in the northwestern region of Hubei Province, China, were analyzed, focusing on extreme environmental conditions. Extreme low temperatures significantly increased ICH risk, peaking around 18 h post exposure, while low humidity was associated with a risk peak at 7 h post exposure. Sensitivity analyses confirmed the robustness of these findings, with extended lag periods showing sustained risk but decreasing magnitude over time. Subgroup analyses revealed higher vulnerability among lobar hemorrhage patients and older adults. These findings highlight the importance of environmental factors, particularly cold and low humidity, in ICH risk and stress the need for targeted public health interventions for vulnerable populations during extreme weather events.