The window unit in my hotel room here in Pointe Noire is suffering from being so close to the ocean. The case is rusting away and last evening the fan started to come loose, wobbling and clicking against the condenser coils. So I switched it off and slept the better for it. Not just the lack of noise but also the fact that the room was comfortably warm rather than shivering cold.
It seems that a lot of air conditioner thermostats simply don't work. As a result the unit is either on all the time or else it's off because you switch it off before frostbite develops and eliminates your extremities. The best example of this was in Venezuela where the office unit developed a temperature that could freeze sides of beef. We used to take fleeces to work to keep warm! And this near sea level a few degrees north of the equator. The alternative was to step outside every hour to warm up in the hot humid atmosphere.
Is air conditioning good for you? Probably not, in that the air is recirculated and germs get to visit every space on a regular basis. The continual noise of window units is an aggravation while the blast of cold air can cause sudden chill downs that might lead to common colds being even more common. On the other hand, when it's really hot and humid and your car is parked out in the sun, air conditioning becomes a godsend. It also allows driving to be a lot more peaceful than when having the windows open, particularly on a busy highway.