Take another look at the original sentence:
You wanted to fix it this way:
To delete the comma between shirt and the would cause an equally bad problem, a fused sentence. A fused sentence occurs when you have two main clauses joined with no punctuation whatsoever. Sylvia shivered in her silk shirt is the first main clause. The difference in temperature between the hot road and the cold library was extreme is the second main clause. The spot between shirt and the needs a stronger break than blank space.
You might want to consult the rules for fixing comma splices and fused sentences.