Medals involve not only the metal itself but also the ribbon, and these materials are susceptible to damage from moisture, dust, sunlight, and changes in temperature. Museums keep medals in locations with regulated temperature, humidity, and light levels to minimize discoloration and deterioration. At home, collectors should keep medals clean and dry, and should store them in a location that is not prone to extreme temperatures. Damp conditions corrode the metals and rot the ribbons, while high temperatures make ribbons go brittle. Acid-free cardboard boxes are a good storage solution, but wooden boxes coated with polyurethane resin are also acceptable. Collectors should avoid polishing medals, as the polish causes abrasion, and they should always wear gloves when handling the medals.
Brazilian Portuguese, which you need to think about more than just believing it's pretty much the same as Spanish, needs some mastering as English or Spanish is incredibly rarely spoken for a developed country and day to day living costs are much higher than the likes of Argentina and Peru or in fact anywhere else south of the USA (Chile and a few Caribbean islands aside). And that's really the deal - as great as Brazil can be, if you have any illusions of bargain travel (akin with South East Asia or Bolivia) and have to watch your pennies plus don't speak a word of Portuguese, it's going to be a lot less fun. You're not quite at European or North American prices, but if you are hitting the big cities and popular beaches don't figure on cheap. A double room in a Rio hostel will set you back over 100-200 Real or 30-60+US$ (although dorm beds are of course cheaper) and (especially when factoring in long distances), bus travel will soon add up. A great network of internal flights are good value and it's when you get away from the major attractions that you'll meet some great fun people from the sexiest nation on earth. Speaking some Portuguese, avoiding any crime and being disposed to 'beach life' are the major factors in getting the very best from Brazil. Those who do will deservedly rave about the place.