Did you not get driven around in a tuk tuk (open carriage pulled by a motor cyclist)? That's a very effective way of cooling down. I used to carry a coat with me. At the end of the day's shooting it began to get a bit chilly for just an open neck shirt.
Being able to employ a personal chauffeur from 6am to 9pm for around US$15 a day was one of the great experiences for me at Siem Reap. Bit bumpy at times though. The roads could do with some improvement.
It must have been a great dealer cooler when you were there. When I was there, it was about 100 F (38 C) during the day, and even at night never got below about 85 F (29 C). We also like to walk a lot, so we were in the guide's car only a very small fraction of the day, to get between far-flung sites.
I hear you about the roads! We took one morning excursion to a place outside Siem Reap with Angkor-era carvings on the streambed (called something like Kbal Spean, I think?), and we were going down the very rutted dirt road at something like five miles per hour the whole way. Of course, when we got there, there were several bus loads of Japanese and Thai tourists...
Just be careful where you step in Cambodia as landmines are still a big issue there.
Land mines are no longer any problem if you stay in the main tourist regions. (Though the occasional unscrupulous guide will try to tell you otherwise to justify their existence, from some things I've heard...)
Re "steffi's" second message: This web site is about photography, not politics, and the regulars here prefer to keep it that way. If you want to complain about political issues, please do it elsewhere