I know I'm the one who triggered this question in a related post. Sorry about that.
For what it's worth, I've removed the lining from two of my AB beaver 'summer weight' fedoras for decades, wearing them in the hot, humid summer heat of South Central-Tennessee, and to date I've not stained either hat with perspiration, and they've been in my possession and use since 2005. That's what the sweat band is for.
That said, though, I do it to reduce a lot of the held heat inside the hat, as has been posted above. It also depends on the material used as lining. Some of the makers use what's referred to as 'wedding silk', which is really elegant, but holds heat something awful. Some even hat a plastic cap that absolutely melts my brain pan when I wear the hat in temperatures above 70 degrees F!
Linings can be removed, and re-inserted when needed, so if you decide to pull the lining out, hang onto it should you decide to reverse the process.
If you're talking about Akubra, they glue their linings in rather than sew them in, so be careful pulling it out if you go that route...at least they USED to glue them in. I haven't handled one for a while, though.
Like I said in the other thread, it's not for everyone. I even used a leather awl and punched vent holes in the side of the crowns of the two aforementioned hats for even more air movement like they used to do in Western worn hats. Stetson, among other hat makers, even sold hats with pre-drilled vent holes back in the 20's through 50's.
I use my hats as tools....items of clothing to keep my head cool in summer, warm in winter, the sun and rain/snow off my head, and if they look stylish while doing it, good for me. I'm at the age I honestly don't care. I want to be comfortable, so anything I've said above should be taken with that caution. It may not work out for you, and that's just fine. I wore hats for years with the linings installed and did just fine.
This being your first, I'd leave it 'as is', and see how it works out for you. You may not WANT to do anything to it. You're just starting on this road. Get the feel of wearing one as it comes out of the box for a while before doing anything as drastic as what I'm doing. That's my advice.
In my case I didn't come to this conclusion until I realized I desired more function over form as I've gotten older, and that's just the way I roll now.
Regard! Michaelson
![Michaelson :M:](./images/smilies/Michaelson.gif)