Should I still go volunteer at the library with a little cold?

Last night I started having hot flashes, tossing and turning, aching and coughing. I’m not aching anymore because I took ibropofin. I still have a cough and a bit of a soar though, stuffy nose. I’m not badly sick, I just don’t feel well. One of the girls said, “Well you promised you would help…can’t you toughen it out for two hours? You can toughen it out and then go home afterwards. Some people go places where there a little sick. There’s people that go to work sick. Come on (my name). You HAVE to come.”
What do I do? Nobody believes I’m sick and I can’t just stay home will a “little cold”. Come on, there’s still covid around. I don’t have a fever which is good. Mine is 98.5.