My 5 month old has a temp of 100.2 she has a runny nose and has been crying on and off. what could this be? is it concerning? what should i do?

Many causes: As a fellow midwesterner, i know there is still lots of RSV and some influenza b still around. With low grade fever like she has, i suspect a virus causing a cold (upper respiratory infection or "uri", could be RSV if coughing alot or wheezing with it. Getting more fussy (crying on and off), could indicate a complication like an ear infection, which commonly accompanies colds in babies.