Without any idea as to what your growing conditions were like and what the environmental conditions of the outdoors area you brought them out to was like on that day, I'd guess that it is either cold damage or a bacterial infection.
It would help a lot to get some environmental information in order to properly diagnose such a problem.
Helpful info would include:
1. Growing area parameters.
a) Temperature (day/night)
b) Humidity
c) Lighting
2. Outdoor parameters.
a) Temperature (whatever time of day it was when you brought the orchids outside).
b) Humidity
c) Lighting
Sunbaked. It doesn't take much. Cut off the leaf all the way to the base, cauterize with cinnamon on the cut edge and don't water for awhile. Poor thing. But I must say....wow!!!! Video!!!! Gosh I wish I could do that. It would be too cool.
Most camera phones have a video feature. Virtually anybody can take short videos now.
Uploading the video onto YouTube is easy if you have a YouTube account. It's just that it takes a long time to upload depending on how long the video is.
I did what everyone suggested, the next day cut the leaf off near the base with a sterile razor blade and put cinnamon on it.
Two days later came home from work and went to check on it and the other leaf also looked like it was heading this way and smelled like rot. Picked up the pot off the shelf and the whole plant just fell apart in the crown. It was very sad.
Likely sun damage from the Sunday watering ritual, which I will now do in more shaded area. The weird part was that every other orchid I had seemed totally fine, not a single sun spot or anything, and this one suffered so fatally.
Strange thing...
Anyway, thank you for the help, and yes that was just my iPhone that I took the video with and uploaded directly to YouTube. Only took about 20min to upload as it was a 2min video over Wifi.
Very nice video. Uh, what's wifi? You Tube? I'm just a Neanderthal. And old too. I have a gov phone and so video something? I'm lucky they let me use it as a phone.