Walking through a forest trail lowers the heat strain on the human body significantly faster than walking on asphalt roads in the city, according to a field experiment by the National Institute of Forest Science, a research body under the Korea Forest Service, conducted amid Korea's ongoing summer heat wave. The institute tested the cooling effect of Hongneung Forest, an experimental forest in Dongdaemun District that dates to the Joseon era, by using thermal imaging cameras to compare pedestrians' heat response while walking on a forest trail versus a nearby asphalt road. Participants who walked the forest trail saw their average facial surface temperature drop by as much as 1.9 degrees Celsius from their starting point, and it stayed about 1.7 degrees lower even after the walk ended. On the asphalt road, by contrast, the average facial surface temperature — 37.0 degrees Celsius at the start — jumped to 38.1 degrees in the first stretch and showed little improvement by the end. Averaged over the full route, facial surface temperatures were 1.1 degrees lower on the forest trail tha