As omicron cases have soared in San Francisco and so have calls to 911, straining the system and eliciting a plea from officials Saturday for local residents to limit calls to severe medical emergencies. San Francisco Fire Chief Jeanine Nickolson said calls to 911 for medical assistance have jumped from 300-330 a day to more than 400 over the last week. "We are seeing a surge in 911 calls which is putting a strain on the system and what we are also seeing is many of our members off with COVID," she said during a Saturday news briefing. "So there is a supply and a demand issue." "We are really urging people to only call 911 for life-threatening emergencies," she continued. "Please don't call 911 to ask for a COVID test or because you have a cold or minor flu symptoms. We really want to keep our ambulances available to people having a heart attack or strokes…It is the transport side of things that is really challenging for us right now."