Improperly sized or poorly maintained air conditioners can lead to discomfort, higher energy bills, and reduced cooling efficiency. Residents in Milwaukee, where summer temperatures can soar, are particularly at risk of heat-related discomfort if their cooling systems are not optimized. Additionally, units installed in direct sunlight may work harder, further reducing efficiency and increasing costs. The advice provided by Consumer Reports aims to mitigate these risks by promoting informed purchasing decisions and regular upkeep.