Watch out for the spontaneous combustion of automobiles caused by willow catkins (Source:)
Spring is the season of poplar and willow. You know, willow catkin contains a lot of grease. If it enters the car radiator, it will cause excessive temperature or poor thermal insulation, which will accelerate the aging of wire rubber, crack or melt, and cause short circuit or fire.
Source: Online Responsible Editor of Chinese Police: Liu Yuxin_NBJS7825