Cultural aversion to bathing? Maybe in some places but baths were an essential part of Kievan-Russian culture since recorded history began there. For peasants AND nobility. It was customary to bathe a minimum of 3 times a week. Mothers were required to bathe every day for 40 days before and after birth. In the winter you had hot bath shacks and in the summers you had the cool rivers. They made their own soaps from animal fats/skins. Teeth were brushed with crushed minerals and various herbs. Not as convenient as hot showers today but people were definitely FAR from filthy.
Air conditioning wasn’t as necessary when you had no concrete and plenty of trees to moderate the heat. I spend ~50% of my time in a rural home fully shaded by trees and never used air conditioning there once. The AC has been sitting in a box since I brought it there 10 years ago. When I go to the nearest town, the temperature there is 10-20 degrees hotter than my home. Taking advantage of shading and natural air currents, people lived without AC for all history. Yes, weak people would die in a random extended heatwave. They can also die any day today if their power randomly goes out.
Yes, doing farm work in the heat is terribly hard but fields today still don’t have AC and likely wont for a long time. Yes, adults had to work sunrise to sunset for food/heat. But today most people sit in a damn office sunrise to sunset. Humans were designed for moving and sweating all day. Not sitting at a damn desk stressing over petty politics.
I think we are talking past each other. I am NOT talking against the virtue of working hard all day, sweating and earning your labor the manual way. In fact, it does help you burn fat, which the modern man certainly needs.
What I am trying to get across is that the life before modern comforts, including modern medicine and hygiene practices, was hell (by modern standard). You cannot have bygone era peasant walk a modern hallway and not have the entire building evacuated for foul smell, dripping dirt, and untreated pathogens like smallpox, TB, and plague.