What should you support a cast with while it dries?

Supporting a cast with pillows while it dries is the best choice because this method provides the necessary cushioning and elevation needed to help prevent complications such as pressure sores or indentations in the cast. Pillows can help to keep the cast in a stable position while allowing for proper ventilation, which aids in the drying process. This option is particularly advantageous as it offers both comfort and support, ensuring that the cast does not shift or become misaligned during the drying phase.

Using towels may not provide the adequate support needed for a drying cast, as they could absorb moisture and potentially become damp themselves, leading to issues with the cast. Plastic covers can trap moisture and heat against the cast, which is counterproductive for drying. Books may not offer a suitable or secure support to maintain the correct position of the limb, and using them might risk not providing even support, leading to discomfort or an improper fit once the cast has dried. Thus, pillows are clearly the most appropriate choice for supporting a drying cast.