Whipped cream is fine if it doesn't get warm. It helps to have something to stabilize the cream a bit (eg. a bit of sugar or powdered milk). If you're particularly concerned, you can always add gelatin... just make up the gelatin first (about 1/2 a teaspoon to 1 tablespoon of water for each cup of cream), let it cool to room temperature, and whip it in at the end of whipping the cream.