Hi Angel,
I'm sorry to see one of your babies in critical condition.
You said you "When we leave the house and turn the A/C off, it gets about 90F in here."
I've read in numerous orchid books that the temperature can get
high in the room for phals as much as 85-90F with sun hitting their leaves through a curtain. They will do fine as long as they have
good air circulation via a fan, and when you touch the leaves it doesn't feel warm.
In my experience so far (have been keeping orchids for a only 4 months) I keep a floor fan on in my bedroom and let the temperature reach 85F with my phals 1 feet away from the southwest window. The temperature is hot but when I touch the leaves of my phals they are cool to the touch which is a good sign that the sun isn't frying them
I let the temperature reach 85F because I've read higher temperatures promotes leaf/root growth. So far so good!!
By your pictures it looks like your baby is fighting for the life to live. Don't give up on it!! Discern what advice to follow and buy yourself another phal at the same time. This is a situation you can learn from to help your future babies stay healthy.
I'm rooting for you and your baby, Angel
and thank you for sharing because I'm also learning with you.