This varies, you still see some polyphasic sleep in countries that have very hot middle of the days, Greece + Spain off the top of my head. An intentional waste

This varies, you still see some polyphasic sleep in countries that have very hot middle of the days, Greece + Spain off the top of my head. An intentional waste of daylight because the cooler mornings and evenings are better, but industrialisation has still reduced the frequency of these practices.