I think my 10 year old female cat has a cold. Symptoms sure look like it.

My ten year old cat has been the healthest to date.  So obvious that she is not feeling well right now.   I live in a bad air quality town so I was wondering if she could be developing allergies.  For a few days now she has been sneezing consistently.  My house is generally too cold, so she loves being in the patio soaking up sun.  I don't blame her.   Now she has a runny nose and red eyes lids.  With mouth partially open, I can see that she is starting to breath like I would with a stuffed nose.  I am trying to get into the vet's office but darn it if that they are so busy.  Anyway to make her more comfortable until they can see her?

You can get a baby humidifier and use it near her to keep her nasal passages open. You can also run a hot shower and then bring her in the bathroom with the warm steam for a couple minutes. Please make sure she is always sneezing that way you know her passages are open. I'd call the vet tomorrow morning and push for an appointment. A cat with its mouth open is never normal and a sign that the cat needs care very very soon. It's not akin to a human with a stuffy nose breathing with their mouth open. Your cat is struggling if her mouth is open. Please keep her sneezing and call the vet tomorrow morning if she continues to have her mouth open.