Feet Severely Burned. Redness, Swelling On Skin That Didn't Burned. Is It Normal? Medication?

My 16 y/o son works at a restaurant. Last Sat night he was burned very badly when a vat of hot grease spilled over both feet . The tops of his shoes and socks were practically melted and the tops and sides of both feet have first, second, and third degree burns. On Thursday, an urgent care physician debrided the burned skin and gave us one small sheet of aquacel for a dressing change. We just removed the aquacel. Of course, there is raw flesh where it was burned (probably 1/3 to 1/2 of the top and side surface area), but where the skin was not burned has become red and swollen. I have two questions. 1) Is the swelling normal for this type of injury or is this an indication of infection? and 2) What kind of ointment or treatment can I use to re-dress the burn? A friend of mine is an RN and suggested Milk of Magnesia or Solarcaine, but I want to be sure I m doing no harm. Thank you so much for your help! It s 7:30 on a Saturday night (1 week from the burn) and I need to know what to do so he can sleep tonight.