Urine smell from A/C

Does anyone know why a vehicle's A/C would smell like hot urine?!! Please advise. I own a 2004 Chevy TrailBlazer. It takes your breath away.

Well, here is one reason (this happened to me)

http://www.automotiveforums.com/vbulletin/showthread.php?t=448910

Otherwise, I would suspect you have a neighbourhood tomcat (not neutered male cat) who is marking your car as his territory, and has chosen to stand on your hood and pee in your air vent by the windshield. (how charming).

Short of a well-directed shotgun blast, some hardware stores and pet stores sell a scented spray that you can use around and on your car which wards off animals.

Maybe someone wanted to piss in one of your water holding things. or maybe you just need to change your air filter or something.

Check your cabin (passenger) air filter. Istructions should be in the owners manual. Be ready for sticker shock when you go to buy one.

I cut out the old filter material and cut a piece of furnace filter and stapled
it in place a the plastic frame work (this was for a Montana Mini Van) The price was $40 plus for the filter. This worked well but may not be a good fix for your auto.

This reminds me of that guy with the Infiniti G35. mildew or something was infecting his AC and he even got sick and he complained to Infiniti. Doesn't mean you're getting sick, just that this is what it reminds me of.