run a fever
Also, run a temperature. Suffer from a body temperature higher than normal, as in She was running a fever so I kept her home from school. These idioms use run in the sense of “cause to move,” in this case upward. [Early 1900s]
How To Cut Down Run-On SentencesA run-on sentence is a sentence where two or more independent clauses have been incorrectly joined together. An independent clause contains both a subject and a verb and can stand on its own as a complete sentence. Some examples of independent clauses include “Jane ate dinner,” “John went to the store,” and “Sue made a pie.” Comma Splices A comma splice is a grammatical error …
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.