I have baseboard H/W heat...heat ok on 1st floor, no heat on 2nd floor....I have thermostat up to 73

You have not given any information that leads to an answer. I guess you have a pump to circulate the water, and maybe the pump is not working. Maybe the pipes are not insulated so the water loses heat as it goes up. I can only suggest that you get a plumber to look and see what's wrong.