See if the hotel has a gym. If so, you can use it. If it has a pool, use it (swim a few laps if possible, get in the deep end and tread water). If the hotel is in a pretty safe area, go for a run or a walk.
Are you a returning student? If so, then you should be able to use the gym at your school.
For bodyweight exercises: pushups, planks, squats, lunges (forward lunges, lateral lunges, walking lunges, runner's lunges), standing abductions, bridges, bridge-ups, single leg-bridge-ups.
Try using the workout generator: www.sparkpeople.com/resource/fitness_plan_