The study looked at how cities can get hotter over time due to changes in the environment. Using satellite images, researchers found that in Nanjing, China, the heat in the city moved from the outskirts to the center and got stronger each year. Factors like new roads, changes in city borders, and building projects all played a role in this. The findings can help other cities with similar heat problems plan better for the future and make their cities more eco-friendly.