We're moving to the UK, and so our 10 year old lab is going tio live with our daughter and granddog in Miami. I've been researching, and it seems that they won't let the animal go if the temps are greater than 85 on either end, which means that I need to leave DEN in the afternoon and arrive in MIA as late as possible. I'd prefer a non-stop to avoid stress on my doggie.

I'm planning on flying UA, but that isn't mandatory. I appreciate comments on other threads about lettting the agents, pilot, etc. know there's precious cargo in the hold.

Take a photo of your dog. Once on board, ask the pilot to check the cargo for a dog. This is important, as they will engage the temperature control. If and when he/she returns, ask him/her to describe the dog in cargo. Show him/her the photo to confirm. Personally, I would take the first flight of the morning rather than the later flight.

Your pilot is not going to be able to visit your dog. It is the rampers that load pets into the cargo bin and animals are loaded last. Paperwork is filled out and handed to the pilots advising them that they have an animal on board, so that the heater and oxygen is turned on.

You can ask the F/A's if they can check to see if your dog has been loaded. They will ask the pilots to check with the rampers.

Suggest you take a red-eye non-stop flight to MIA due to the temps on the ramp.

Suggest you take a red-eye non-stop flight to MIA due to the temps on the ramp.I would second this suggestion. Unless you are planning for a fall/winter trip, it gets hot early and stays warm late in MIA. Unfortunately, all of the red-eyes I see from DEN have a stop on the east coast before going to MIA, arriving after the temps start rising. Perhaps route via the west coast for a 6AM-ish arrival?

And note that some airlines outright ban all "checked" pets during summer months. For example, DL will not accept pets as checked baggage from May 15 through September 15. As cargo, animals are allowed year-round with temperature restrictions and cargo fees.