SAN DIEGO (CNS) — Changing climate in California is reducing the number of people dying of cold temperatures, but increasing heat-related emergency room visits, according to a study released Wednesday by UC San Diego researchers.
The study, a joint collaboration between UCSD and Stanford, found that as the average temperature increases, fewer Californians die during cold weather. While more people are now dying of extreme heat, the pure numbers of those not dying during low temperatures outweigh it.
However, higher temperatures cause a sharp increase in ER visits.
"Heat can harm health even when it doesn't kill," said Carlos Gould, assistant professor at the Herbert Wertheim School of Public Health and Human Longevity Science at UC San Diego and first author of the study. "Warmer temperatures were consistently associated with more trips to the emergency department, so studies and planning that only consider mortality miss a big slice of the burden."
The researchers used data covering all deaths, emergency department visits, hospitalizations and daily temperatures in California from 2006 to 2017, publishing the findings in Wednesday's edition of the journal Science Advances.
According to the data, emergency room visits rise sharply with hotter days. Injuries, mental health issues and poisonings show marked increases with heat but are not major causes of death, so they are often missed in studies that focus only on mortality, the authors write.
"Age plays a critical role in shaping health risks from temperatures," Gould said. "Older adults are particularly vulnerable to cold temperatures, whereas younger adults and children are more affected by heat."
The benefit of fewer people dying of cold-related causes may be offset by the many hospitalizations and emergency room visits, the authors write. They suggest health policy needs to account for this trend as climate change continues, with hospitals, insurers and public health agencies preparing for higher demand during heat events and tailoring heat warnings and resources to different age groups.
"We often think about only the most extreme health impacts of heat waves: deaths. This work is showing that many things that we may not think about being sensitive to extreme heat are, like poisonings, endocrine disorders, injuries and digestive issues," said Alexandra Heaney, assistant professor at the Wertheim School and co-author of the paper. "We need to focus on the full spectrum of health impacts when we think about heat waves, now and in the future."
Using projections based on moderate climate change scenarios through 2050, the researchers estimate California will see around 53,500 fewer deaths overall due to less cold weather -- partially offset by an estimated additional 1.5 million heat-driven emergency department visits.
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