I am planning to take my son (22 yo) to Asia next September for 2 weeks. I am getting a bit overwhelmed on what to do.

Right now I am looking at flying into to Toyko for 2 nights (son request). Then flying to BKK. From BKK I was trying to get in Chiang Mai and Siam Reap. On the way home I was planning to try to get Hong Kong in for maybe 2 nights. Do you think it would be too much to also try to fit in Ho Chi Minh? This is really going to be whirlwind but I would like to fit in as much as possible but also make sure I am hitting the prime areas. Any suggestions???? Thanks.

My suggestion is to pause and consider what you really want to do/see/experience in Asia. You're talking about a huge area here. In two weeks, I generally recommend no more than three stops, but you might do four. Five and you'll never know what you did other than spend time in airports.

In addition to Tokyo, Bangkok and Siem Reap, I'd consider the Golden Triangle area (north of Chaing Rai) rather than Chaing Mai. If you want to go somewhere in VN instead of Chaing Rai, I'd suggest Hanoi rather than Ho Chi Minh.

september is not a good time in bkk in general as the weather is poor---tons of rain... could you wait until late october??

not sure about the other areas..

It will be hectic but is doable. I would say 2 complete days is the minimum reqd to see the main temples at Siam Reap - we did it in Feb and the pace is bruising but is manageable. 3 days is a more comfortable pace. Bear in mind this entails getting an early AM flight into Siem Reap and the evening flight out the next day. Also, it will be HOT in Sept as it is most of the year - do not know what temperatures you are used to. I agree with Kathie that if I were to choose 1 place in Vietnam it would be Hanoi. In Thailand I would say spend longer in Bangkok rather than trying to add 1 more place - Bkk is a great city and you will have loads to do there. While I enjoyed Chiang Mai I would not put it on a MUST do list. 2 days in HK is VERY short esp coz the airport is not that close to the city - spend 2 nights at least to get some flavour of the place.

Well I pretty much have my itinerary set. Here it is:
Tokyo 2 nights
Bangkok 4 nights
Chiang Mai 2 nights
Siem Reap 2 nights
Hong Kong 2 nights

I have already warned my son there will be no sleeping in and to be prepared. That's okay, after reading some of these posts I think I am going to make appointments in the evenings for massages. That should help us.

I was in BKK this past September for a couple of days. So I have seen some of the temples. I plan to try to hire Ratt to take my son one day to the temples while I enjoy a spa day. I also plan to do a one day tour to River Kwai. My son would also like to attend a Thai boxing event so hopefully something will be available.

Any more suggestions for any of our stops are very welcome.

You guys are great with all your input and advise. Thanks again.

i may be in the minority, but the river kwai is not really a very exciting destination and with your time constraints i would consider using that day for something else, unless you have a particular reason to visit there...imo

And I'd cut out Chaing Mai and put one more day in Siem Reap and one more day in Hong Kong...