Your body heating up could be related to anxiety. I have found that anxiety and/or adrenaline can cause this. If you relax, you may find that this goes away. However, sometimes this heat could just be part of your particular experience. It's different for everybody.
also, in Robert Bruce astral dynamic he talks about mind split and missed exit...is it possible to control your astral double trough the silver cord if you had a missed exit and the double haven't return, kind of like a remote control?
I'm not sure you fully understand the mind split concept. Remember, with mind split there is two of you. You are conscious in two places at once. So there is no need to take control of your astral double since you are already in control. (But your physical may never know this) However, you can force a synchronization of both consciousness using Astral Feedback as a method, but be careful.
To avoid missing an "exit", or a better way to put it is, to avoid shadow memory loss.. you need to keep your first projections very short. 30-60 seconds and tell yourself that you will remember everything when you wake up. The reason you want to keep your first projections short is because you can remember 30 seconds of something a lot easier than an hour worth.. and your physical consciousness will still be in Focus 10. This will allow a better memory download.
As time progresses, you will be able to project for longer periods of time and get better at storing memories. But the best way of dealing with your problems (we all have them at first) is by keeping things short and simple.
I hope this helps!