Cities with more connected urban development, regardless of how dense or spread out they are, tend to have hotter temperatures compared to surrounding areas. The way cities are built can make them trap heat, creating what's known as the urban heat island effect. This effect can have negative impacts on people's health. By studying the 50 biggest cities in the US, researchers found that increasing the connectedness of urban areas by 10% can raise temperatures by 0.3 to 0.4 degrees Celsius. This means that planning cities with more disconnected areas could help reduce the urban heat island effect and keep cities cooler.