in regards to altitude, you really need to look at where you (how high) will be. If you are hunting around 6000' and under Brock A is correct, most will only feel short of breath. The difference is when you climb higher. When you begin entering a higher elevation above 8000' (good rule of thumb) you may begin to encounter problems. At around 8000' you begin to see altitude sickness in some people, and in some people you can develop HAPE, high altitude pulmonary edema. HAPE typically is seen at higher elevations, but cases have been seen at or around 8000'. As you climb higher you can see HACE, high altitude cerebral edema. Now none of these altitude problems effect everyone, and effect people the same when they climb into higher elevations, so don't let these terms prevent you from hunting these higher elevations. There are tactics and medications one can use to help alleviate the symptoms and possible development of altitude related problems.
The best plan is climb high sleep low, just as it sounds. This will also help with acclimatization to altitude. Slow ascent is the key, if you cannot drive to your destination and must fly there, a night or two in a lower area, but still within 2000' of your target altitude will help. Unfortunately some people will never acclimatize to altitude, but most will just fine. And as always hydration is a huge component.
I hope this helps, PM if you have anymore questions.