Rising temperatures can come with risks far beyond the physical dangers of extreme heat.
Warmer weather is associated with an increase in violent crime, even during the winter. It’s correlated with increased incidents of hate speech, harassment and discrimination. High temperatures have been known to have adverse effects on mood, increasing irritability and symptoms of depression.
Now, new research finds that warmer weather can increase the risk of substance-related hospitalizations.
The study, published today in the journal Communications Medicine, finds that higher temperatures are associated with more hospitalizations related to the abuse of alcohol and drugs in New York state. For nonalcohol substances, hospitalizations increased until temperatures reached about 50 degrees — then tapered off.
The researchers, led by Robbie Parks from Columbia University’s Mailman School of Public Health, compiled hundreds of thousands of hospital records related to alcohol- and substance-related disorders in New York state between 1995 and 2014. They then compared these records with temperature data from the same period.
They also controlled for potentially confounding factors, like seasonal patterns and long-term trends in hospitalizations.
Some overall patterns emerged. The majority of hospital visits were composed of people between the ages of 25 and 44, and there were more men than women. Both alcohol- and substance-related hospitalizations increased throughout the study period, with substance-related cases driven largely by increases in hospitalizations related to cannabis and opioids.
And spikes in temperatures caused hospitalizations to rise, even as much as six days later.
The findings point to “some less obvious potential consequences of climate change,” Parks said in a statement.
It’s unclear exactly why these associations exist.
Other studies have suggested that warmer temperatures can have adverse effects on mood and mental health, potentially increasing the risk of substance abuse. Warmer temperatures may alter the physiological effect of alcohol or other substances on the body, increasing the risk of hospitalizations for some people. People may be more likely to go out and socialize with others in settings where alcohol or drugs are present when temperatures are higher.
It’s also unclear why substance-related hospitalizations peaked at a certain point. It’s possible that past a certain temperature threshold, the weather becomes comfortable enough that people aren’t any more likely to go out and socialize.
Still, that’s just speculation. The study doesn’t actually explore the causes behind the associations — those are questions for future research.
The study has some major limitations. It focuses only on New York state, and it’s unclear whether similar results would be found in other parts of the country with different climates. The researchers also note that certain populations are likely to be more vulnerable to alcohol- and substance-related hospitalizations, including people with preexisting health conditions and unhoused populations. The study doesn’t explore the effects of those factors either.
Still, the research lays the groundwork for another potential side effect of rising temperatures. It’s a pattern public health experts should keep an eye on, the researchers suggest.
“Public health interventions that broadly target alcohol and substance disorders in warmer weather — for example, targeted messaging on the risks of their consumption during warmer weather — should be a public health priority,” study co-author Marianthi-Anna Kioumourtzoglou of Columbia University said in a statement.