You will not be in a 40-50 hrs/wk job. Your hours will be closed to 60 hours considering the useless meetings that you have to go through especially as the BDE Surgeon. You will learn to bow down like a loyal pet saying Yes, Sir to orders to your commanding officer regardless of reason and safety. Depending on your commander's discretion, shadowing might be a no-go.
In the field, you will join the enlisted soldiers in the first couple of days setting up the Role 2 hospital. That means unloading 5-6 heavy 500-600 lbs tent soaked with water and sand, and then setting them up. You will join the enlisted soldiers setting up medical emergency supply chests that could easily weigh 40-50 lbs each. For a Role 2 hospital, there are like 20 chests. For some field exercises, you will move to a different location like 3-4 times. That means packing and unpacking your equipment 3-4 times. Everything needs to be packed, unloaded, and reset within 10 hours depending on the mission objectives. You will learn to eat MREs twice a day, forcing you to push out bricks through your anus on a regular basis. On areas where there are no portable toilets, you will dig a hole in the ground and take a dump. For some locations, you will learn to use a WAG bag to properly store and dispose of your feces. You will learn to breath in sand through your mouth and nose especially during a sandstorm, and you will learn to cope with it. Last but not least, you will never look at a regular toilet in the same way again. This is just the surface of what you will be doing. If you are fine with it, the next step is to talk to some HPSP docs. Once you have done these steps and are still hooah about it, your recruiter will help you with your transition to the USA.