Extreme Temperatures Are Associated with Increased Mortality Rates

Earlier this year, the AMA joined multiple other organizations and identified climate change as a public health crisis. Extreme temperatures and air pollution have considerable healthcare implications, including increased rates of tickborne illness and respiratory issues. A recent article published in Circulation added one more impact to that list. Researchers found that extreme global temperatures are linked to increased rates of cardiovascular cause-specific mortality.

Researchers in the study looked at data from 1979 to 2019 across 27 countries. Investigators in the article note, “to investigate cardiovascular mortality associations with extreme hot and cold temperatures, we fit case-crossover models in each city and then used a mixed-effects meta-analytic framework to pool individual city estimates. Extreme temperature percentiles were compared with the minimum mortality temperature in each location. Excess deaths were calculated for a range of extreme temperature days.”

The study examined all cardiovascular deaths, including ischemic heart disease, stroke, heart failure, and arrhythmia. According to the study, extreme heat, temperatures in the 99th percentile, and extreme cold, temperatures in the 1st percentile, were linked to significantly higher rates of cardiovascular deaths across all countries.

Extreme heat increased the number of cardiovascular deaths per 1,000 by 2.2. Additionally, extreme cold was associated with a 9.1 per 1,000 cardiovascular death increase. More specifically, heart failure had the highest increases in mortality rates on cold and hot dates.

The study authors concluded, “across a large, multinational sample, exposure to extreme hot and cold temperatures was associated with a greater risk of mortality from multiple common cardiovascular conditions. The intersections between extreme temperatures and cardiovascular health need to be thoroughly characterized today — especially under a changing climate.”

Climate change has and will continue to impact healthcare and public health. Beyond cardiovascular deaths, climate change is linked to increased asthma rates, lung issues, cancer, infectious disease, and tickborne illness. With this in mind, healthcare professionals must consider a patient’s environmental factors when diagnosing them. Additionally, public health efforts should include advocating for improved efforts to minimize climate change and sustainable practices, thus minimizing its public health impacts.