In the clothing to choose from, there is one essential. It can make all of the difference between being comfortable or real torture. In the not too distant yesteryear, they were referred to as long-johns or long handles. In our modern society, we have given them a scientific name - Base-Layer. It is superior insulation without the bulk of old school layering up. When hunting and fishing, freedom of movement is at a premium.
In reality, these are not the cotton variety made years ago. The modern version is truly a thing of sophisticated technology. With differing weights of material depending on the varying temperatures you may face in the great outdoors, these things feel more like neoprene wet-suits. They insulate very well while wicking away excess moisture and are worth every penny you will pay for them.
I was truly a skeptic before wearing some. Trust me, they make a radical difference when facing the elements.
I will tell you that all of these are not made equal. The more expensive versions are priced the way they are for a reason. Under Armour is the true leader in this market. They are also the most expensive. Boasting Base-Layers for any climate and even offering scent control technology to aid a hunter to defeat the nose of a monster buck.
One note on the Under Armour brand is that they make things to fit super tight which I do not like. The shirt isn't too tight but it's a good idea to get a size larger than you are used to wearing. The pants are tremendously tight. When taking a bathroom break from a wheelchair, tight is not what you are looking for. I recommend to go a couple sizes bigger than your average.
RedHead made by Bass Pro Shops is every bit as good as Under Armour. On top of this, it is typically about $30 cheaper on average and also offers scent control technology. And, it doesn't fit as tight as Under Armour.
For some strange reason, I actually enjoy wearing the Under Armour top with the RedHead bottoms. I am not exactly certain why, but I do.
What I do know is, 1. I hate being cold and 2. I like being warm without having the weight and 3. I like having confidence in the gear I use. So, whatever works for you, I encourage you to stick with it. Good luck in your late-season hunting adventures!