I should have qualified what I said to be with regards to normally healthy people. For most people, air conditioning and central heating is a completely wasteful luxury that churns through shitloads of resources for soft idiots who can't deal with reality and/or don't have the common sense to move somewhere with a climate more suited to them (if you can afford to centrally heat your home, you can afford to move somewhere with a climate more suited to you). Now, if you've got a medical condition that's aggravated by certain weather, then of course central heating and air conditioning's going to be a good idea and I'm not going to criticise anybody who has it.
The reason I slam "bloated Americans" is that almost the only people I know who are so lazy and materialistic as to have central heating (something I associate with shopping centres, office blocks, and other large developments) are Americans. None of my family have anything like that in their houses in New Zealand or Australia. Neither do my friends, with the exception of Fellow Albino Railfan who requires it due to medical reasons. I once lived in a house which had a wall-mounted air conditioning unit for the downstairs living area, and we never used it because it churned through our power bill, and frankly a fan does enough of a job.
Hell, I'm so cheap and so unwilling to churn through electricity that I keep putting off buying an electric blanket!