Let me share some HOPE... When my husband would wake up his brain didn't work at all. He would slur words (major cotton mouth from lack of moisture). He wouldn't sleep well at night and would drift off all day long... and I mean ALL day. He even got to the point where he was falling asleep on his feet or falling over and sleeping WHEREVER he was. Also his memory was toast! He could barely think his way out of a paper bag.
I took him in for a sleep study and found he needed a BiPAP (also called VPAP, step up from CPAP) machine. After the first night he was a lot more normal. He had some increased energy, his memory was way better and he was thinking much clearer. And best part for me he isn't falling asleep all day long.
As for the heat issue he has that too. My assumption is from his meds? But he is always turning on the fan and I am always piled in blankets. I don't have anything great for that one but if someone else does I'd love to hear it! LOL