Calm a first time mamas nerves

My son is 2 years old and just woke up out of a dead sleep and threw up everywhere! he’s never done that before. I got him cleaned up and he went right back to sleep. I felt his forehead and he feels hot. Should I be worried? It makes me more nervous, because he was at his grandmas house today, and apparently her son had a stomach virus the day before! Could he have gotten it?