Cause of mystery sickness that left 27 runners in hospital during Santa Barbara Half Marathon

Santa Barbara County health officials say unusually high temperatures combined with exertion during Sunday’s half marathon appear to explain why dozens of runners became ill and 27 went to hospital. They said there is no sign of a wider public health risk, addressing rumours that water at the event had been contaminated or tampered with.

Temperatures reached 80°F (27°C) by 10am and rose into the mid-80s, around 10°F (6°C) above what is typical for the November race. Twenty-four patients were treated and released, while three remained in hospital, according to the Associated Press. Inspectors found no food-safety concerns at the site where electrolyte drinks were prepared, but their checks did not determine whether anyone could have interfered with hydration stations during the event; police enquiries were ongoing.