I had to return my work Android phone to my employers when I left. I just remembered it was signed into my Hotmail account. How do I prevent others from getting access to it?
Changing the password is probably easiest and best option.
From which medium are you accessing Hotmail from - mobile site or using their app?
If you were accessing Hotmail using their app,it's also recommended to clear all your email data too so as to prevent unauthorized access to your account.
To clear all data go to Settings-->Applications-->Manage Applications and locate the Hotmail app.Tap on it and tap on clear history and clear data.
If you were accessing Hotmail using their site then you can sign out from sign out button present at the top right side of it.Also, make sure that to clear the browser history from which you were accessing Hotmail.