5 Silent Signals You Can Use to Tell Someone You’re in Trouble You may never plan to use these signals — but knowing them can save your life or someone else’s. Each one is designed to blend in during danger while still alerting others. Practice them. Teach them. And remember, awareness is your strongest protection. The more people who know, the safer everyone becomes. 1. Palm up, tuck thumb in, close fingers — this is the global hand signal for help. 2. Blink rapidly twice — subtle way to alert