Buck, alot of hunters get sick during hunting season for a variety of reasons but here are some very important ones:

1) their diet goes to heck---hunters begin to eat alot of fast foods or sandwiches, and forget to eat vegetables and fruits..thereby depleting their body of minerals and vitamins

2) With work and hunting, something has to give, and usually it is sleep. Every few days when you are hunting hard, sleep in one morning until 8am or so, and hunt the second shift from like 10am-dark...will keep your nervous system in check

3) People tend to drink more stimulants and that tends to burn your nervous system out, then leads to your immune system breaking down...cut down on the coffee for a few days when you are beginning to feel sick, will help you stop getting sick

4) people get sweaty walking into their stands, then catch cold while on stand as a result of the moisture

Anyways, you probably already knew that stuff, but in case you didn't, just modifying a few things each day will keep you alot healthier during the season...good luck buckmaster519~