My boss had asked me if I might be interested in some extra paid hours for work this week, but realizing that it's Valentine's this week, work will be exceptionally busy and rather demanding, realizing I'd need to give my best effort several days in a row (which is next to impossible, knowing that no one can be next to perfect several days in a row). So I gave the boss a call... We settled on an extra shift of work after Valentine's Day also knowing that "truck day" would be the day previous, also when my work shift was included. ("Truck day" is when new product arrives from the warehouse) Usually, the boss doesn't need me the extra day, but thought to offer the extra hours because of Valentine's Day and that our business would be swamped with customers on "truck day" itself, which would mean the boss would need extra employees to cover in following days so product could be put out on shelves. I could use the extra money, but don't need the added stress. In your opinions, what is the polite way to let my boss know that "giving 100% all the time might lead to employee burnout?"