LOS ANGELES - As the second major heat wave in weeks bears down on Southern California, experts and authorities are warning the public to take seriously the health dangers of extreme temperatures that are only getting worse due to climate change.
If the past is any guide, Los Angeles will see a spike in 911 calls, emergency room visits and deaths during a powerful heat spell that's expected to peak Sunday, with highs between 110 and 120 hitting inland valleys and 95 to 105 degrees along the coast.
"Heat of this magnitude is rare, dangerous and very possibly deadly," the National Weather Service warned. Temperatures will remain unusually warm overnight - in the mid-70s and 80s - "creating a dangerous situation where it will be difficult to cool off without air conditioning."
Wildfires, elevated smog levels and possible power outages may pose additional threats. The pandemic, meanwhile, could make this Labor Day weekend especially deadly, as coronavirus restrictions have closed many of the cooled indoor spaces that usually offer relief.
Exacerbating it all is climate change, which researchers say is increasing the frequency and intensity of extreme heat events. As greenhouse gases continue to rise globally, heat spells of this severity are an unfortunate reality that Californians will increasingly have to get used to, they say.
Last month's heat wave, one of the worst to hit California in years, brought "an increase in health-related emergency room visits in relation to the sustained high temperatures," the Los Angeles County Department of Public Health said in an email. "We are particularly concerned that these extreme heat events and the health impacts from them have been increasing in recent years due to climate change."
Though extreme heat is a less visible menace than, say hurricanes or wildfires, it is climate change's most life-threatening impact, causing more deaths each year in the United States than any other weather-related problem, including all floods and storms combined.
"Of all the climate change exposures we study, heat is the number one killer," Rupa Basu, chief of air and climate epidemiology for the California Office of Environmental Health Hazard Assessment, said in an interview last month.
People aren't only dying from conditions such as heat stroke and dehydration. Extreme heat increases risk of complications and death from an array of other chronic illnesses including kidney disease, cardiovascular disease and diabetes.
"Most of the time you won't see it on a death certificate, because people with underlying conditions are pushed to the edge," said Dr. Jonathan Fielding, a UCLA professor of public health and medicine and former L.A. County public health director. "They have a cardiac condition, they have a respiratory condition or other conditions, like COVID. So I'm very concerned about it, and I think it's really important that people take this very, very seriously."