We have camped in "civilized" camping sites, with a general store close by, and a pool, and we have been primitive camping, where you hike in your own water.
Most of the time, the land is clear and all have obeyed the rules of "leave no trace."
however, one year my son was getting water at a spigot between campsites, and received several fire ant bites that caused him to have need of steroid treatments and is now the proud carrier of a personal epi pen.
How did the ants come to be there?
Well, despite the signage on the water spigot that says, "Do not rinse out mess kits here" and "keep area free of food" it turns out that someone had been washing food containers out all week there, and ants congregated.
Nothing like driving 30 minutes down a windy road into an unknown town just before the emergency center closes so your son can get swelling and hives treated.
As for babies/kids left in hot cars, I have NO words that can be written here.