How do you keep your wits about you when you are really tired?

I just started a new job and I’m liking it so far, but as a manager I’m working 50 hour weeks. A lot of the time that includes opening the store at 6am, and it takes me at least an hour to get there. Add getting ready in the morning and I’m waking up at 4:30. I’m really, really tired, but at least there’s an endless supply of free espresso there.

It’s important to be organized and keep my wits about me, but being so exhausted and caffeinated makes me forget everything and make all kinds of stupid mistakes. On my first day, I left my phone at work, then I came back to get it and got my phone but forgot my purse. On my second day I accidentally left $100 in change at the bank (luckily the teller was honest and I got it back.) These are all split-second things where I feel like I just blacked out for a second and things went wrong, so it’s nothing I can deal with using typical organizational methods or planning ahead. How do you deal with this?