First came the fires. Then, there was ash and contaminated water. Now, some survivors of the Southern California wildfires are dealing with outbreaks of norovirus and other stomach ailments at a shelter set up to help evacuees.

Illness typically lasts for one to three days but people can still be contagious after their symptoms have subsided.

A nasty stomach bug has been spreading across the country, including California, in recent months—leaving people feeling nauseous, achy or worse.

The Pasadena Public Health Department reported Friday there was an outbreak of the gastrointestinal Norovirus at the American Red Cross’ Pasadena Evacuation Shelter.