Heat Stress at Playgrounds A case Study in Gothenburg, Sweden

Abstract: The climate will change in the future as it will become warmer with higher temperatures generating extreme weather events such as heat waves. Children are a particularly vulnerable group when it comes to being exposed to heat which is partly due to the fact that they have a harder time thermoregulating themselves. Previous research has investigated heat stress in playgrounds in warmer climates and in preschools in a Nordic climate. The studies have found that Tmrt is affected by both vegetation and shade, and that children show signs of behavioral change when subjected to heat. This study has modeled Tmrt in SOLWEIG on 189 playgrounds in Gothenburg, Sweden, planted trees in TreePlanter according to the most optimal location to lower Tmrt on the playgrounds, then modeled Tmrt once more to find out how much Tmrt has been reduced by placing trees on the playgrounds. Interviews were conducted at the playground Plikta, in Slottsskogen where twelve people were interviewed about the perceived heat and shade at the playground and for playgrounds in general in Gothenburg in the summer. They were also asked questions about how heat on playgrounds affects their children and what playgrounds lack in terms of shade. The results of this study indicate that as many as 108 playgrounds (≈57%) out of 189 playgrounds have an average Tmrt of > 47 (°C). Such high values of Tmrt increase the risks of the playgrounds exposing children to heat stress and thermal discomfort. The results of the interviews show that children are negatively affected by being in playgrounds on hot summer days without enough shade. This study also concludes that the use of trees for shade is a good alternative for hot playgrounds. By planting only one tree per playground Tmrt has shown to be reduced and by planting only 4 trees per playground, Tmrt is further reduced. Planting trees will therefore reduce heat stress experienced by children when visiting playgrounds and increase children's thermal comfort.