In the midst of sweltering summers and rising global temperatures, air conditioning has become an indispensable part of modern life. It promises relief from heat, enhances productivity in workplaces, and ensures comfort in our homes. Yet, behind this technological marvel lie complex issues that demand our attention.As we seek to cool our environments, we must confront the profound environmental, economic, and health implications of our reliance on air conditioning. This book delves into both the applications and the often-overlooked harms of air conditioner usage, aiming to provide a balanced exploration of its impact on our world.Through detailed examination, we uncover how air conditioning influences energy consumption patterns, exacerbates urban heat islands, and contributes to greenhouse gas emissions. We scrutinize its effects on indoor air quality, respiratory health, and even psychological well-being. Moreover, we explore the economic costs, infrastructure challenges, and disparities in global access to cooling technologies.