text:  So, I mean, when we think about how to stay cool when it's super hot in the middle of a heat wave in a city, you think about a swimming pool. You think about maybe a trip to the beach. You think about staying indoors and the air conditioning. But you say that the key to staying cool in a city is trees. You mentioned that a young tree has the cooling effect equivalent to 10 air conditioners running for 20 hours a day. Explain that to us, if you can, Nadina.