Consider this – with such a diverse range of temperatures around the globe, from 58C (136F) in the Libyan Desert to -88C (126F) in Antarctica, how can it be healthy to centralize the climatic norm of millions of houses into a six degree (42.8F) band. The idea that humans are most efficient working within the 18-24C (64-75F) is called thermal monotony and its what architects spent a large majority of their time working on in the years prior to air conditioning.
Historically drier states in the southwest used stone houses to absorb heat during the day and release it at night, while the humid states of the southeast utilized big verandas and breezeways to maximize shade and airflow. Palace designs in India show built oases dug out from three meters underground to combine cooling from below surface with evaporative cooling of the water to contribute to overall cooling of the building. This method has in recent times been recreated and modernized in structures such as The Pearl Academy of Fashion in New Delhi.
By no means is this article advocating to throw out A/C systems – they are a big reason why billions of people can live in the climates they do. Without them them there would be mayhem displacing everyone into the narrow landmass of comfortable temperatures. I am, however, saying that prior the days of air conditioning people survived the climatic extremes with environment specific built homes. While on an individual level it may be time to step away from thermal monotony and only focus on specific rooms of you house as opposed to cooling the basement you enter once a year, on a holistic planning and engineering level it is time to look back at utilizing examples of housing in the past to redesign and shape houses to obtain the most efficient amount of heating and cooling possible.