Freezing the citrus slices keeps this refreshing punch cold without using ice.
Line two baking sheets with plastic wrap, and set aside. Slice lemons into rounds as thin as possible. Arrange lemon slices in layers on one prepared baking sheet. Repeat with oranges; layer on second baking sheet. Place in the freezer for 2 to 2 1/2 hours, until fruit slices are frozen.
Just before serving, open the cans of frozen lemonade and orange juice, and place the frozen concentrates, whole, in a large punch bowl. Add the soda, Southern Comfort, and several handfuls of ice. Remove frozen fruit slices from freezer, and arrange over the top of punch. Serve immediately.