Can flu cause a temp up to 102 degrees? how about a cold? how do you primarily differentiate the two?

Cold vs flu: Colds often are without fever, and usually not as high as 102. Other differences: influenza doesn't usually cause much nasal congestion (stuffy and runny nose, sneezing); colds do. In addition to fever, flu often causes body-wide muscle aching; the common cold usually does not. Still, there's much overlap, and flu often needs an antiviral drug like Tamiflu. So check with your doctor if in doubt.