Every morning when I get up and grab my 2013 rMBP 15", the bottom is warm. This happens after being put to sleep by the drop down in OSX or closing the lid. Everything is updated. iTunes not running. Time machine shows backup completed last the night before while in use. Only Safari with many tabs open and a couple excel spreadsheets are active. Activity monitor show no unusual activity. How can I find out what this thing is doing all night?