I get low grade fevers with my allergies and can relate to this. The saline helped me too, but the netty pot, in particular has been a real help clearing out the sinuses. I had a reaction to the Astelin, it increased my anxiety, heart rate, (felt like I was coming out of my skin), and headaches (besides those caused by the sinus pressure) yet helped only little with the allergies. Perhaps consider trying something else. You may find it is either helping more than you think or there is something better out there with fewer side effects.