Getting my car ready for the hot months ahead, what's on your to do list?

With temperatures already starting to climb, I’m trying to be proactive this year instead of waiting for something to go wrong. I’ve been looking around for general summer car care recommendations because last year my AC started acting up right in the middle of July and it was miserable. I’m planning to check all the fluids this weekend as a start, since I know from experience they take a beating in the heat. But I’m wondering if there are other things people here regularly do before summer really hits. Do you focus more on the cooling system or are there other areas that tend to cause problems when it gets really hot? I’d love to hear what actual drivers do, not just what the manuals say.