Alginate sets quickly, which is perfect for working with young children. If you need a little more working time, you can use cooler water (temperature guides are provided in your kit instructions booklet). Warmer water will make the alginate set quicker, so it’s best not to guess the temperature. If you don’t have a thermometer handy, just use cold water. We normally suggest avoiding casting on really hot days as the room temperature will also make the alginate set more quickly.