Rinsing your nasal passages with only plain water will result in a severe burning sensation. Use lukewarm distilled, filtered or previously boiled water, properly mixed with NeilMed's Sinus Rinse packets. Do not use tap or faucet water for dissolving the mixture unless it has been previously boiled and cooled down. Do not rinse if nasal passages are completely blocked or if you have an ear infection or blocked wars. If you have had recent ear or sinus surgery, contact your physician prior to irrigation. If you experience any pressure in the ears, stop irrigation and get further directions from your physician. Read and retain the enclosed brochure, if provided, for instructions and other important information.