Hot weather may double or triple heart-related deaths: Study

Given the consistently high temperatures in Kuwait (average ambient temperature 27.8 degrees Celsius), researchers examined the relationship between temperature and more than 15,000 cardiovascular-related deaths in the country.

The highest temperature on earth in the last 76 years, 53.8 degrees Celsius, was recently recorded in Kuwait.

"While cardiologists and other medical doctors have rightly focused on traditional risk factors, such as diet, blood pressure and tobacco use, climate change may exacerbate the burden of cardiovascular mortality, especially in very hot regions of the world," said Barrak Alahmad, a mission scholar from Kuwait University and a PhD candidate at Harvard University in the US.

According to the researchers, all death certificates in Kuwait from 2010 to 2016 that cited "any cardiovascular cause" for individuals ages 15 and older were reviewed for the study, published in the Circulation: Journal of the American Heart Association.

Compared to the number of deaths on days with the lowest mortality temperature (average daily temperature of 34.7 degrees Celsius, when the fewest people died), when the 24-hour average temperature was extreme (42.7 degrees Celsius or higher),  the researchers found overall, a three-times greater risk of dying from any cardiovascular cause.

Men were more affected by the extreme temperatures -- experiencing a 3.5 times higher death rate and the death rate among women was nearly 2.5 higher.

The working-age people (ages 15-64 years) had a death rate 3.8 times higher and the death rate was just over two-times higher for people 65 and older.

According to the researchers, when core body temperature increases, the human body tries to cool itself by shifting blood from the organs to underneath the skin. This shift causes the heart to pump more blood, putting it under significantly more stress.

A collaborative group of cardiologists, environmental health specialists and epidemiologists hypothesised that increasing temperatures in hotter regions of the world could lead to increased CVD death due to extreme heat's effects on the body.