SAN FRANCISCO (KGO) -- The thought of "killer heat" might feel like a foreign idea right now, especially with all the fog rolling into San Francisco this week.
But a new report on climate change shows a much hotter future for the Bay Area and the rest of the U.S.
It says urban areas could bake for days in temperatures above 105 degrees if no action to reduce heat-trapping emissions.
RELATED: Researcher explains why climate change could be linked to thousands of dead mussels in Bodega Bay
The report titled "Killer Heat in the United States: Climate Choices and the Future of Dangerously Hot Days," was released Tuesday by the Union of Concerned Scientists.
It shows the number of "dangerously hot days" could quadruple in the U.S. in the next few decades.
"Across California, nearly 11 million people would be exposed to 30 or more days with a heat index above 105F in an average year," said the report.
RELATED: San Francisco restaurateur behind new climate change surcharge coming to your restaurant bill
It could get even worse the Central Valley. Scientists say cities like Fresno could "face the equivalent of two to four months' worth of days per year with a heat index above 105F by late century."
The report features four different heat index thresholds, each of which brings increasingly dangerous health risks: above 90 degrees, above 100 degrees, above 105 degrees and "off the charts."
"We need to take aggressive action. Our challenge is great, but the threat of not meeting it is far greater," said the report.
Go here for more stories, articles, and videos about climate change.
Bay Area could bake in 'killer heat' above 105 degrees if climate change not addressed, report says
More TOP STORIES News