By Geoff Herbert
syracuse.com
SANTA BARBARA, Calif. — Health officials have revealed what they say caused a mystery illness for more than two dozen runners in a California half-marathon.
At least 27 participants in Sunday’s Santa Barbara Half Marathon were hospitalized for “unusual symptoms,” according to Santa Barbara Cottage Hospital. The Associated Press reports 24 patients were treated and released, while three remained in the hospital in stable condition.
Cottage Health confirmed it had a “larger than expected number of emergency visits... with similar symptoms of undetermined cause,” prompting a police investigation. The Santa Barbara Police Department said the victims, who had all participated in the 13.1 mile-race, arrived by ambulance, self-transportation or as walk-ins.
But on Monday night, the Santa Barbara County Health Department said the cause of their health issues appeared to have a simple explanation.
“At this time, the medical incident appears to be an isolated event connected directly to race participation and the heat. There is no indication of a broader public health concern or ongoing risk to the community,” the health department said in a press release.
According to the Independent, temperatures were roughly 80 degrees on Sunday, about 10 degrees warmer than past years for Santa Barbara’s annual November event.
Online rumors suggested water stations may have been contaminated or contained drugs such as ketamine. However, health officials said inspections found no violations or areas of concern at the hydration areas.
David Monico, event director for the Santa Barbara Half Marathon, told NBC that “there’s always a handful” of people needing hospitalization after a long-distance race. Warm weather and intensive exercise can lead to heat exhaustion, regular exhaustion and dehydration.
“But this year, it was more than we’ve had in the past. We also had more runners than we’ve had in the past as well,” Monico said. “There was a lot that has been said on social media and was circulated, and so (the police are) doing their due diligence to see if there’s any facts and truth behind it.”
“There was no unusual symptoms or anything outside of the norm for a half marathon or a marathon or some type of endurance event,” Monico added, according to the AP.
According to race organizers, there were 7,500 registered participants in the half-marathon, which began at 7 a.m. Sunday.
Police say the investigation remains ongoing. Anyone with information is encouraged to contact Santa Barbara police Sgt. Andre Miller at 805-897-2330.
©2026 Advance Local Media LLC.
Visit syracuse.com.
Distributed by Tribune Content Agency, LLC.