HOUSTON (AP) — An elected official in the Texas Gulf Coast town near where Hurricane Harvey is expected to reach land says residents who chose to stay should write their Social Security numbers on their arms.

Patrick Rios, the mayor pro tem in Rockport, told KIII-TV of Corpus Christi earlier Friday that Harvey “is a life-threatening storm.”

He says those who stay “should make some type of preparation to mark their arm with a Sharpie pen,” implying that they should make it easier for rescuers to identify them.

Local officials along the Texas coast urged residents to take precautions and, if they were in the direct path of the storm, to evacuate. Thousands of people have headed north so far.