I don't agree that most hotels don't have aircon - it's very rare I've stayed in one that doesn't, and nor would I unless it was guaranteed to be cold.
It's worth remembering that energy is a lot cheaper in the US than here, so while I don't think the power consumption is the main factor (plenty of people have tumble dryers, which are horrific in terms of energy use), it's just not a priority when it would only be needed maybe two weeks of the year even in the South. Many buildings are old and would be hard to install it, and most of the new ones are cheaply built at best.
That said, you can buy a small aircon unit for less than £100 and if I didn't have it built in at my work flat I would have done that rather than use a fan to just push the hot air around. Had it not been for mine I would not have slept for the last week and definitely not have worked - it was 38 degrees here last Friday and just impossible. If it breaks down, the agency get it fixed.
As for tumble dryers, I had to finish some work towels off in mine last night to stop them drying all cardboardy and it was like fucking Hades in here until I caved and put the aircon back on. Thank God it's settling down a bit.