First of all you probably need to not wear the wig when slopping the pigs or gathering the eggs. Those kind of chores seem to really take a toll on the ole hair piece. But if this is not your case then you probably just need to replace it with a better quality of horse hair and not synthetic materials.
As far as the southern climate goes; that will only make that cheap ass make up run but I have never known it to cause a wig to split its ends. However with all the heat down here in the south you definitely don't want to get too close to any open flamers.... whoops! I mean flames in either case. I would really hate to see you go up in smoke! NOT!!!
Just keep your head up and keep on smiling! And remember, only 6 more crazy checks away from Christmas! Save...Save.....Save.....