Assuming you are in reasonably good health, you will get used to it. As others have said, you will learn to work around it. For example, you might play golf early in the morning instead of mid-afternoon. Likewise, you might do some yard work early in the morning or wash your car etc.. Then save the afternoons for indoor activities like reading your newspaper or whatever.
What do you do up north when it's freezing cold? Do you stand out in the cold all day?
No, I don't think so. Well, it's basically the same idea here, just different weather conditions.