this happen 4 times in my life but im pretty sure it happen when i was young.

it recently happen, and occurs mostly in summer time. I go to sleep and in the middle of the night i have like a weird dream. the most recent was well i don't really remember but it was kind of like something really boring, counting grain or something. I was half awake and i started to walk around. I drank water but it didn't seem to help. While i was half awake I think my heart rate got really fast and everything seems like my mind is slower then my body. Like i will walk, but i walk faster then normal, and my vision is like a laggy computer (choppy). There no physical, but its like stressing my mind when it happens. I also don't remember
exactly what i did, or what my dream was about.
When im half awake sometime, i close my eyes and my mind is like moving up and down, like im seeing it but im not moving.
I also sometimes have dreams that im afraid of or thoughs, i would be playing like some kind of game and i cant wake up. So im playing a game over and over again.

note form:
-sleep walk, dizzy, half awake most of the time when it happens, stressing my mind, increase in heart rate, mind feeling different from body (choppy/laggy vision and fast walking or speaking maybe from panicing)
-say weird things, like "save the game"
-happen 2-3 times a year, mostly in summer

Is it because of the heat or something? even though it wasn't that hot.

I would visit a doctor but as you could tell i cant really explain what happened. Can someone give me some disorder or something that might be it, so i can look it up and see if its correct, then i can explain to my doctor better. If you need more info ask me anything.