You really shouldn't be eating food that has been left out for more than 15 minutes. Foods like hot dogs are potentially hazardous and need to be kept out of their temperature danger zones. Hot dogs should be heated before being eaten and they should not be eaten if left out.
It depends on how long they've been left out. Hot dogs aren't very good for you anyway so I probably wouldn't eat them if they weren't properly refrigerated.
No! Never eat anything that has sat out for more than an hour or two. It could become contaminated and you could in turn get food poisoning from it. Remember to place all of your food back in the fridge when you're done.
