A foot locker with a
Good Lock/ heavy duty, also a small safe that will hold a lap top, extra keys, wallet, any electronic's, anything with personal info, ie Social Security cards, insurance, jewerly etc...
If he has a bike a really good lock, mark the bike and
take pictures, of everything.
Make sure he knows not to leave his laundry unattended, they will take his clothing, especially towels in a dryer - laundry soap, dryer sheet, whatever is unattended or lying around, I don't think that most see it as stealing.. more of hey I need that so I will just take it with me.
Also with the bathroom at the end of the hall, If it is like a locker room style, get something that he can keep his shampoo, and soap, razor/ shaving cream that can go in the shower with him. My friends son was in the shower, and came out and someone took his towel and shaving kit off the bench right out side the shower, where he was at. So she went an bought a plastic basket, the kind you can use for putting cleaning supplies in, and her husband drilled holes in the bottom, so the water could flow out, so it could sit in the bottom of the shower, then she took his towels and put button holes in the corner, and added shower hooks so that someone would have to reach up and in the shower to take the towel. when he would do laundry he would just take the hooks off and then put them back on, worked great.
Even apartment style living, my DD lived in a share apt style dorm, 4 bedrooms with each their own bathroom within each room, and shared living room, and kitchen, We changed the lock on DD's door the 1st day, Food is another big thing, I would take DD to the store and her dorm mates would help themselves to whatever was there, even though the cabinet were marked with their names. So we bought a storage cabinet at Ikea for her to keep food, linen, towels, paper products etc.. We also bought a small frig. for her room. He room was tight, she had a day bed, dresser, desk, and storage cabinet and shelf's that we put up over the desk, but for her is was perfect, and she did not worry about having her stuff gone through or taken, which gave her more time to worry about important things, like what see was going to wear out that night
Its a wonderful time for them, but they need to be aware of what's going on around them.