I think a normal human being takes fifteen to thirty minutes to fully wake up. When I am driving an ambulance vehicle, I get four minutes.
Normally, the first minute is taken by waking up and calling my co-driver, that we have a mission to accomplish. On our pager I can only see the priority of the mission, a rough description of the location (mostly the place) and an indication of the mission (Stroke, Heart Attack, and many more other short words).
The second minute is used to go to the toilet, as I don't like driving off with a full bladder if you don't know when the next occasion to pee will be.
The third and fourth minute are almost always the same, jump into cloths and walk to our car in the basement. In the car, I am reading through the whole information our dispatch collected and check it as read. Then our dispatch knows we are in the car and will drive off in the next few seconds.
I wouldn't say that this is good for your sleep pattern if you do this multiple times in a night, but it taught me one thing: Getting up and be immediately able to handle a situation. Normally I would be driving a car by the fifth or sixth minute, which isn't an easy task if you ask me.
Also, my brain and the brain of my co-driver start spilling out ideas what could potentially have happened at the patient's location. Everything just four minutes after waking up.