Any time you have a serious emergency requiring emergency response at work, you should call 911. See Chapter 1 for more information on when to call 911. In addition, you should call 911 if you or your coworkers have any doubts or concerns, even if you aren't sure the dispatcher knows how to help. When calling 911 from work, you need to remember to dial any prefixes necessary to obtain an outside line before dialing 911. In most 911 calls, a computer in the dispatch center shows the number and address of the phone you're using, but at a workplace the location of the main switchboard may be the only location appearing on the dispatcher's computer, so it's important that you provide accurate directions.