Foam Cups Insulated for hot or cold beverages. Foam cups are designed to maintain beverage temperature. Dart insulated foam cups come in various sizes. Not only do foam cups keep beverages at their proper serving temperature, they also protect hands from extreme temperatures on the outside. Hot or cold, insulated foam drinking cups deliver your beverage just right. Foam cups are ideal for coffee, tea, cappuccino, hot chocolate, hot cider, soda, juice, water and other soft drinks.