What to do the summer between high school and college?

So I’m trying to figure out what to do this summer. I want to go to medical school and for the past three summers I have worked at a materials engineering lab doing research. As for this summer, I have a few options. I could work in a different lab doing research I am more interested in, I could take a computer science class at a local university for free, or I could just have fun this summer and prepare for college. As for college, depending on a few things I will most likely either be in a BS/MD program or at a different university not in a BS/MD program. So does this summer really matter?

Do nothing! Enjoy your last summer of relaxation. Or, get a part time job to save up some spending money for when you get to school.

Get a part time job and save money for school. Volunteer at a hospital to make sure you like the medical environment if you aren’t already.

My S will get a job part of the summer and study a language abroad the other half.

You should not do nothing.
If you have an idea of the classes you are taking, you should pick one or 2 classes, look online at the professors syllabus, buy the book they teach from or something similar, and study the heck out of it so that your freshman year can be easier if you already no the material.
Don’t work before college because you can make money and pay for your college once you have a job that actually pays well.