How Can Sinusitis, Rhinitis And Nose Blocks Due To Allergies Be Treated?

I have sinusitis, running nose, nose block problem due to allery to dust, etc. I am going to Srinagar this December end and would be there for 4 days and back to Delhi. Presently I started taking Montek LC in advance as the temperatures in Srinagar already dropped to -5 degree centigrade. Please suggest me what are other precautions should I take?