Was this sleepwalking?

Maybe you were just drowzy, or in the middle of your deep sleep?
You stepped into the outside of the house (and woke from the change in temperature)?
Was alcohol involved?

I don’t have first hand knowledge with sleepwalking other than a friend who did it. When she was staying at my house, I’d wake up in the middle of the night with her standing beside my bed staring at me. Actually, she wasn’t staring “at me” but rather “through me”. I could tell that she wasn’t looking at me & IF I said anything to her, there was NO response. She’d suddenly turn & go back to her room & back to bed. The very first time it happened, it really creeped me out. Once I learned what it was, it didn’t bother me that much. Her doctor just said to NEVER startle her awake & to just tell her to go back to bed or take her by the hand & lead her back to her bed. There were a couple of times that I heard a noise & got up to check & found her raiding the refrigerator for a midnight snack.When I said something to her about it, she didn’t want to believe it.

Now, my ex was a heavy drinker & I’d occasionally be awakened to him standing in the corner of the bedroom peeing in the corner. IF I’d ask him what he was doing, he’d respond I’m in the bathroom…I’ll be back in a minute. When he finished, he’d come back to bed. Fortunately he never did more than pee!!! I chalked his up to being in a drunken stupor & not to sleepwalking…it only seemed to happen when he drank way too much!!!

I don’t think this would be considered sleepwalking, but it was probably related to whatever you were dreaming.
Sleepwalking occurs when there is a failure by the brain to sort of paralyze you during sleep.
You probably woke and acted on some instinct related to activity in your dream.

Yeah alcohol was involved. Yes I stepped outside my room before I realized what I was doing.

Then it might very well have been causing this event.
See also @LadyMarissa‘s answer, about the man peeing in the room.
My brother has done the same, in the corner of the corridor, leading up to his room.
Another time, he was drunk (as was he in the pee event), he climbed over a rail that separated the landing from the stairs, and fell down one story, on his back.
We thought he was dead, but fortunately he only had some backpain (and abrasions).

The outside/temperature I mentioned because that sudden difference could have been just the trigger to wake you fully (otherwise it potentially could have been a longer trip).

You might have been sleep walking.

@SergeantQueen Your Q had a related Q from 2012 that caught my eye. One reply had this related info attached to it & I thought you might find all of this interesting. One specific jelly related their experience with sleepwalking which I found very interesting. It may well give you some insight into what you’re experiencing!!!

I don’t think you can look at it as though you were suffering from Somnambulism because you say you were awake, or at least half awake.

I am afraid this kind of thing happens to many people during their lives.

In my case I was a child and I dreamed many times that I had to have light before the clock struck midnight. Then the clock started chiming and just before it reached the twelfth chime I opened my eyes and I was standing right next to the light switch and the room was bathed in light because I had switched on the light.

I had this same dream many times and the result was always the same but I never consider it as sleepwalking.

Consider blackout.

Very dangerous territory. Suppose you didn’t wake up but instead got behind the wheel of your car.

It sounds like “sleep drunkeness”:
https://health.clevelandclinic.org/everything-you-need-to-know-about-sleep-drunkeness/