- leave a note on their desk for them to discover when they come in.
- call them on Thanksgiving and say a quick but sincere thank you (yes an email could work too, but please don't add a to-do to that email. Just a thank you and be done.)
- leave a yummy surprise in the staff kitchen and email them a note to go find it and enjoy.
It's nice when you have time off to celebrate the holidays and it's nice to be acknowledged if you're the one working so that others can have time off.