In Science, Year 5 explored which materials are the best insulators at keeping the contents of lunch box either warm or cold. We tested different materials such as bubble wrap, tinfoil, fabric and plastic by wrapping them around a container filled with ice. We measured the temperature at the start, then at 5 minute intervals up to 25 minutes. If the temperature stayed low, then the material was a good insulator because it stopped heat getting in and melting the ice cube. If the ice melted a lot and the temperature increased, it was a good heat conductor of heat, so not a suitable material for our lunchbox.