>You should not **work** in the field while the sun **was** hot.  

I came across this sentence and it felt a little odd, The original sentence is not from a native speaker. I think it should be either:

>You should not **have worked** in the field while the sun **was** hot.

or:

>You should not **work** in the field while the sun **is** hot.

Maybe dropping "while" would be a better idea, but my question is- can a sentence have two different tenses like this?