Seem to have sinusitis after a flight. had to be outside in the cold for an hour today. symptoms slightly worse. seek care or push fluids and rest?

Try the latter first: Most sinus infections are viral and hence self-limiting and will resolve on their own in about a week. Rest and fluids is a great idea. A humidifier or warm shower and inhaling the steam may help. Over the counter remedies such as nasal steroid sprays, "sinus rinse or netty pot" may offer some symptom relief. If fever and/or worsening symptoms then pursue follow up.