Guns: Warm Weather CCW
"Summer concealed carry" is a bit of a meaningless concept here in South Florida. For about half the year, it's hot and humid enough outside that you'll be warm no matter how light your clothing is. Depending on how much you sweat, it can become a huge challenge to conceal a firearm using traditional carry methods.
For me, a waist holster is impractical when the weather's boiling. IWB rigs attract too much moisture from the body, while OWB rigs require a covering garment that'll make you even hotter. Consequently, I pocket a J-Frame revolver in the summer months, and it works well enough.
Even pocket carry requires certain clothing, however; it's impossible with athletic shorts or sweatpants. For those who absolutely need to carry a gun in such garments, a SmartCarry/Thunderwear type deep concealment holster may be the answer:
There's also the option of off-body carry, usually inside a purse or bag of some sort. There are plenty of reasons to shy away from this type of carry (e.g. if you lose your purse, you lose your gun), but it's better than not carrying at all:
A final option for summer CCW is the unconventional waistband holster, one that encases the gun itself. Examples include the Wilderness Safepacker or this BullDog cellphone-style belt case: