Going back to the states in a few months for a short visit. I will bring back flat sheets as Thai's don't use them (similar to europe) and can be hard to find here.
Thailand is 220 V 50 cycles. Devices with a motor will not work unless they are dual voltage. Phones & laptops are fine. Best example I can think of is even if you use a 220v to 110v converter an analog clock will run 10 minutes slow every hour.