After the events of Iron Man 2, Tony added a chunk of code to JARVIS’s programming that lets his computer disregard a questionable order and prohibit him from using any Iron Man suits if his blood alcohol level is above a certain point. If something life-threatening happens while Tony is too drunk to use the suit, every Avenger or other peaceful affiliate (Pepper, Rhodey, Happy, etc.) in the same postal code is informed of the danger.
Pepper, Rhodey, Clint, and Natasha are by default allowed to use and control the suits, but only if someone’s life depends on it. Tony says it’s because “Non-super superheroes need something extra, sometimes.” (He never bothered redefining his reasoning after Pepper ended up with the Extremis. They don’t mention it.)
