Simple Science @Heart: Extreme temperatures may raise risk of premature heart-related death
Just a two day “heat wave” may increase the risk of premature heart-related death.
Researchers found that a heat wave – the hottest one percent of temperatures – for two or more days led to increased cardiovascular death risks. The scientists compared heart-related deaths and daily temperatures in Brisbane, Australia, over an eight-year period.
The average daily temperature in Brisbane is about 69 degrees. Heat waves in this study were defined as two or more days at 85 degrees or hotter.
Researchers say extreme temperatures can trigger changes in blood pressure, blood thickness, cholesterol and heart rate. They said the increased death rate might be because people become exhausted due to the sustained strain on their cardiovascular systems without relief, or because health systems become overburdened.
Cold spells – the coolest one percent of temperatures – were also linked with increased deaths, but not as high as during heat. Cold effects lasted longer than heat effects, with the peak in cold effects coming two days after the temperature drop.
Spending a few hours daily in a temperate environment can help reduce heat- and cold-related illnesses and deaths.
Stories available for linking, quoting, excerpting, reprinting
Stories appearing on blog.heart.org under the "By American Heart Association News" byline are available for linking, quoting, excerpting and reprinting. Copyright is owned or held by the American Heart Association, Inc., and all rights are reserved. Permission is granted, at no cost and without need for further request, to link to, quote, excerpt or reprint from these stories in any medium as long as no text is altered and proper attribution is made to the American Heart Association. Additional conditions may apply to the use of these stories in printed materials.
American Heart Association additional conditions for linking, quoting, excerpting, reprinting stories in print media
- A credit line of American Heart Association News must be prominently placed on the page in which the American Heart Association materials appear.
- The American Heart Association logo and service marks may only be used if they appear on the materials requested.
- Stories reprinted may be edited for length, but no other deletions, alterations or other changes may be made without the prior written consent of the American Heart Association.
- Artwork labeled "American Heart Association" may be reprinted, but other artwork may not. For artwork permission questions, contact email@example.com
- Stories reprinted may not be placed adjacent to any advertisement, photo, graphic or other content that could be considered inappropriate by the American Heart Association. For questions about whether content is inappropriate, contact firstname.lastname@example.org.
- Stories may not be displayed in any way that gives the appearance that the American Heart Association endorses (implied or otherwise) or is affiliated with any product, service or company.