In some parts of the world, extreme heat can be far more dangerous than cold. When AC is not an option, it's usually possible to avoid trouble by staying in the shade, drinking a lot, and limiting physical activity. If it gets really nasty, the best way to cool yourself is to wet your clothing and hair, then stand in front of a running fan. You have a bigger problem if you happen to be stranded in a broken down car somewhere in the middle of a desert - but carrying some water and several other supplies in your trunk should help a great deal. More about that soon.
Now, many "true" preppers would tell you to keep mum about your plans, so that in an emergency, you don't have to fend off armies of freeloaders begging for a slice of your meager supplies - or worse yet, trying to take them by force. I think that this attitude is short-sighted; sure, it makes sense not to broadcast your plans to the entire world, and there is no conceivable benefit to posting Facebook selfies with your stash of freeze-dried food or with a pile of cash. But the clear value of convincing some of your friends to start prepping greatly outweighs the distant possibility that one of them will attempt to raid your home the moment the power goes out.