This is going to be sort of long:
Before your trip look online to see if bed bugs have been reported. Some good websites
www.bedbugregistry.com and
www.bedbugreports.com
Do not place luggage on a bed, ground, or any other furniture before you check for bed bugs. If you have your own transportation you could leave your luggage in the car while you check the room. If not, one of the safest places you can place your luggage is actually the bathtub/shower. Bed bugs tend to not make it that far as they wont be close to their food source.
A small flashlight is handy for checking under beds, long seams and being headboards.
You should strip the bed sheets and any mattress pad to check the mattress. Remember to check box springs or platform beds crevices as well. Pay special attention the seams.
You will also want to check everything else that can hold bed bugs. Bed stands, couches, drawers and furniture.
Adult bed bugs are oval, brown, flat and wingless. They are about the size of an apple seed. Young bed bugs are smaller, and sometimes a lighter shade of brown. Babies tend to be almost a clear color.
Look for rusty or reddish stains on bed linens, pillows, mattress/box spring, frame, headboard, bed stands, walls, etc.
Bed bug excrement leave dark spots that may look like a pencil or pen mark.
Eggs and eggshells are white and are only about a millimeter in size.
Pay special attention to box springs these are a bed bug haven! Platform beds, or slatted bed should also be checked.
You sometimes are able to see shed bed bug exoskeletons as well.
Some tips and tricks suggest to turn the lights off, and use your flashlight, or to turn a hair dryer on the mattress corners for a few minutes to simulate body warmth. The idea is that the warmth and the dark will bring the bed bugs out(as they usually feed at night and when a warm body is in the bed) and you may be able to trick them to come out to find them. I have never used this method because it has been pretty clear but checking the seams, etcs whether or not there may be a bed bug infestation.
If you find signs of bed bugs, and you are not able to change hotels request a new room on a different floor far away from the infected room. Often times the rooms next door, directly above and below can also be infected.
Not everyone is allergic to bed bugs, so not everyone will have a reaction if bitten by bed bugs. This is why it is important to check for bed bugs before you make yourself at home on vacation.
You can use zip lock bags, something called or something called Bug Zip to help encase your luggage/clothing/belongings to help prevent bed bugs. There are plenty of other brands, but Bug zip is the only one I am familiar with. Bug Zips are meant to be left behind for disposal, and not meant to be reused.
http://www.bugzip.com/
Due to regulations in the United Stated the chemicals that effectively treat bed bugs tend to no longer be available. The only way to kill bed bugs seems to be high heats. You should wash everything that can be laundered that way on high heat upon returning home, and dry on high heat. Throw anything else that can be put through a high heat dry cycle through one.
Vacuum suitcases/luggage crevices to get rid of any eggs. Hard shell suitcases are better for preventing bed bugs than regular fabric ones.
www.bedbugger.com is one of my favorite websites for bed bugs tips, tricks, and how to deal.
I am sure that I am forgetting some things, which is why I included the bed bugger website link. I know that with my own experience I became incredibly paranoid along with my 2 girlfriends, my cousin and her friend. I ended up cleaning everything I had with me on high heat, and placing it all in zip locks and trash bags. I cleaned my car, and I threw away my actual suitcase. I had bought new clothes and took an outdoor shower at the rental home because I refused to re -the house. I pretty much lost my mind during that ordeal and developed extreme anxiety afterwards. I now check for bed bugs at very hotel or vacation rental stay and I have bed bug/allergy encasements on my mattress and pillows for preventative measures. FYI the encasement is preventative in the sense that it makes it easier to inspect. Also, Bed Bath and Beyond carries an "all natural" bed bug spray. I bring the travel size one with me, and spray my mattress, and other furniture, just to be safe. It probably doesn't do anything and it smells strongly of cinnamon almost sickeningly so.