I found travelling in Burma (Myanmar) to be the hottest place that I have ever been anywhere that I have travelled. When "out and about" for the day ALWAYS make sure that you carry with you more than sufficient fresh bottled water with you for the day. To say this place is like a furnace is an understatement. The chance of getting dehydrated if not replacing lost fluids is severe. Most of my sightseeing was done by either walking or by bicycle. I found the heat and humidity of the day to be really oppressive and I was used to a very hot and humid climate.
Bottled water I found was not available everywhere that I went , so I used to buy many bottles at the supermarket and keep them in my hotel refrigerator.
WARNING* . If purchasing bottled water in an out of the way place make sure that the cap (seal) is not broken and the bottle is not a "refill" with local water.