The summer semester is only six weeks long, but the chemistry class would include the same amount of work required for the fall or spring semester.

Of course you should, if it opens up areas of study into your goals in the medical fields. There are many.

I wouldn't do it unless it was for a full and complete semester. 6 weeks is a very short period to learn THAT much info.

We do not know you, many Universities have special programs for the shorter semesters, some even in Fall and Spring have sub semesters and other divisions today.

Only you know your ability to do that much work, how much effort you can put into it, and more. Others do it, but if you have doubts of your ability to do it, wait for a full semester