The logic has always been there: hotter temperatures mean higher incidents of dehydration, and dehydration means the liver has to process more concentrated urine, and thus is more likely to be overwhelmed by calcium and other deposited minerals, leading a greater number of kidney stones.
But now scientists have additional proof -- numbers to back up the logic.
In a study of kidney stone incidents in a number of American cities, researchers correlated rises in daily temperature with upticks in kidney stone formation.
The findings were published in the latest issue of the journal Environmental Health Perspectives.
Specifically, researchers at the Children's Hospital of Philadelphia looked at the medical records of some 60,000 adults and children diagnosed with kidney stones between 2005 and 2011 in Atlanta, Chicago, Dallas, Los Angeles and Philadelphia.
"We found a general trend that as daily temperatures increase, there was an increased risk of patients presenting with kidney stones within 20 days of the temperature exposure," explained lead author Dr. Greg Tasian.
"Kidney stone prevalence has already been on the rise over the last 30 years, and we can expect this trend to continue, both in greater numbers and over a broader geographic area, as daily temperatures increase," Tasian added. "With some experts predicting that extreme temperatures will become the norm in 30 years, children will bear the brunt of climate change."