Detailing in the sun is really not ideal. I would strongly advise against it. At least try and get under a canopy or something that will shade you and the car.
Trying to do a multiple step process with polishes and waxes/sealants without a shade for the car might end up as a difficult and bad experience which could turn you off from ever trying to detail your car again.
If you really can't find any type of shade to work under, I recommend that you try and use a product like
Klasse All In One because it goes on quick and easy as a sealant that also has some cutting power when used with a machine. It won't remove heavy swirls, but it has enough punch to remove light swirls and with some patience, some medium swirls.
I use Klasse AIO when I don't have much time or it's way too hot in Arizona to do an extensive detail.