I always get to know when I get closed to getting burn out. Take a day off, go hangout with friends or do some outdoorsy stuff. If you actually keep on working and actually get burned out, it will take you longer to recover. A day or two off won't help, you will need longer.

This burned out feeling is like mold growing up. The more it manages to grow, longer it will take to clean up.

To keep it away, have regular breaks, go out, take your special someone out on a date, just chill w/ good music etc.