When heat and humidity combine: What we learned from 15 years of data
Author: NB-IRDT Staff
Posted on Aug 6, 2025
New Brunswick is no stranger to hot, humid summers—but what happens to health outcomes when temperatures spike?
A recent NB-IRDT study, Health Effects During Extreme Heat Events in New Brunswick: Developing an Evidence-Base to Enhance Adaptation Planning, looks at hospital admissions, emergency department visits and deaths during periods of extreme heat over a 15-year period.
The data show that more deaths and hospital visits tend to occur during heatwaves, especially when high humidity is involved. Urban areas like Fredericton, Moncton and Saint John are particularly affected.
While the study does not determine the cause of death, it identifies clear patterns that point to increased health risk. Even after the heat passes, health impacts continue for up to seven days. This suggests the need for sustained public health measures before, during and after extreme weather.
These insights can help strengthen New Brunswick’s Heat Alert and Response System (HARS) and guide future climate adaptation planning.