I think I'm having physical reactions while dreaming?

It started happening about a month ago and it's been like this ever since then. I started having very vivid dreams about all different things and I'm convinced my body is reacting to them. For example, earlier this morning I had a dream that ended with me giving a thumbs up and when I woke up I was doing just that physically. Then I feel asleep for another hour and had a dream involving a lot of physical activity. I ended up waking up with a very dry mouth and my body feeling exceptionally warm. I have had other dreams lately where I usually wake up with my mouth at least half open or with certain parts of my body in motion. How concerned should I be about this and how can I stop having these reactions? My brother is literary one door away and I'm sure this is very awkward for him and embarrassing for me if my reactions are ever severe enough to be noticed by him.