"Do you have a fever?"
I think 发烧 can be a noun (a fever) or a verb (to have a fever).
The suggested translation is "你有没有发烧" which uses it as a noun. Can you also write "你发烧吗" which uses it as a verb? (it is not accepted).
发烧 is used as a verb in some of the other examples in this topic, so I don't see why it can't be used that way here.
Why is "你有发烧吗“ not accepted? "你有。。。吗？” is functionally equivalent to "你有没有。。。“