Don’t want my new born sick 😣

My son is 5 and I just had a new born baby girl . Yesterday afternoon he caught a fever . No other symptoms besides just a fever . I watch him though the night and gave him Motrin . Today’s he’s still running a fever of 103 I gave him Motrin again and will bring him to urgent care once my husband gets hone to watch our new born . HOW CAN I PREVENT MY NEW BORN FROM CATCHING THIS 😭 ( she’s a premie baby )