The heat-safe play index (H-SPI): a tool to compare relative thermal safety of outdoor playgrounds

Outdoor play is essential for healthy childhood development. In urban areas, public playgrounds are the most commonly used spaces for outdoor play, but they are not always thermally safe. Visitors can suffer from heat-related illness and injury from ultraviolet radiation, radiant heat, hot surfaces and dehydration. Playground design features including shade, surface materials and water availability impact thermal safety, but differences between playgrounds are generally unknown. We developed a 'heat-safe play index' (H-SPI) to compare relative thermal safety (RTS) at 142 public outdoor playgrounds in Sydney, Australia. Results showed that RTS varied greatly among playgrounds: H-SPI scores ranged from -28-92 out of a possible maximum of 100. Thirty-five playgrounds had been recently upgraded, so the H-SPI was used to compare RTS before and after modifications. There was an overall small increase in RTS: 60 % of playgrounds had higher H-SPI scores, but 37 % had lower scores. The H-SPI enables councils to compare RTS of different design options when planning playground modifications, and provide heat-safety information to playground users. This information will allow better-informed decisions that promote health benefits from safer outdoor play for children, and will help to build heat- resilient communities in a warming urbanised world.