In the classroom anything goes. When its hot and dry: shorts, t-shirts, tank tops, and sandals are the norm.
In the hospital it's not as casual, but still much more lax than the States. Pants or skirts of any type and color; that means jeans are ok. Solid T-shirts are good too. For the guys, leave all your ties at home nobody wears them here. As for footwear sandals are acceptable because it's part of the culture; feel free to wear sneakers as well.
As for white coats, there is no ceremony. At the begining of each rotation you get a coat from the hospital which you return at the end. There is no such thing as a student white coat you wear the same thing as the docs.
Hope this helps (I also think this will make for some interesting conversation!)