Paragraphs and indenting

So I'm having a difficult time figuring something out here. Then again I may just be over thinking it.

I hope I can explain this well enough...

I'm currently writing a story and I have come to a part where I have a small idea on how to indent and create paragraphs for it - it involves one character and a body-. There is a lot of description going on with his actions, like checking body temperature, talking to him self and stuff like that.

So instead of just making one big huge paragraph (which I know is wrong!) how would I separate it into proper paragraphs. Would I just separate it and do basic 6 sentence paragraphs or would I do it every time he completes a thought? (if that makes any since what so ever)

Thanks