Buffalo Bills safety Damar Hamlin made his first public appearance since going into cardiac arrest after making a tackle against the Cincinnati Bengals three weeks ago, waving to fans from a stadium suite on Sunday as the two teams met again for an AFC divisional playoff game the Bills went on to lose 27-10.The crowd at Highmark Stadium erupted when an image of the recovering Hamlin filled the massive screens at the end zones near the end of the first half. Fans turned toward the glass-enclosed suite and cheered.Hamlin, wearing a hooded jacket, stood in front of the windows and raised his arms as if saluting the crowd and encouraging it to get on its feet as the Bengals were facing second-and-goal at their 5. He ended by forming a heart sign with his hands, his signature gesture.Earlier Sunday, the Bills posted a video to both Instagram and Twitter showing Hamlin arriving at the team's locker room and the message, "Welcome home, Damar."The video showed Hamlin arriving in a golf cart about an hour before kickoff, wearing sunglasses and a face covering, the hood of his jacket pulled up. He was accompanied by his 7-year-old brother, Damir, and mother, Nina.Bills quarterback Josh Allen described his presence as "a warm feeling.""Obviously, we wanted to play for him ... We just ran into a team that played better than us tonight," Allen said after the loss.Hamlin was not seen before the game got underway in snowy conditions. The Bills made no announcement about his whereabouts, but word of his attendance had spread by the time he appeared on the screens."It was amazing, it really was. I think everybody got so excited," fan Brin Jobson of Buffalo said at halftime. "We heard he might be here, so it was cool to see him."Hamlin, 24, had not appeared in public since the Bills and Bengals last met on Jan. 2 in a game that came to an abrupt halt and was eventually canceled after Hamlin's collapse on the field in the first quarter.Bills coach Sean McDermott said Hamlin began making regular visits to the team's facility soon after his release from the hospital in what he described as "dipping his toe back in here and getting on the road to just getting back to himself."It was "just a great moment" when Hamlin appeared on screen during the game, McDermott said afterward, especially considering that just weeks ago, medical personnel used CPR and an automatic external defibrillator to restart his heart.For several minutes, the television audience that tuned in for that Monday night game instead absorbed the fear and sadness on players' faces, some streaked with tears."Just him being in the locker room (Sunday), his presence was good for the guys," McDermott said.A family spokesman for Hamlin said this week that he still faces a lengthy rehabilitation. "Damar still requires oxygen and is having his heart monitored regularly to ensure there are no setbacks or aftereffects," Jordon Rooney told The Associated Press.The Bills have not disclosed the results of tests Hamlin has undergone to determine why his heart stopped after he was struck in the chest while making what appeared to be a routine tackle.Hamlin, who is originally from the Pittsburgh area, live-tweeted while watching Buffalo's 35-23 season-ending win over New England from his hospital bed at the University of Cincinnati Medical Center on Jan. 8. Last weekend, he live-tweeted from home while watching the Bills' 34-31 win over Miami in a wild-card playoff.