What is the hottest temperature you can donate blood outside to where its not dangerous?

My lil sister went and donated to the american red cross. The held the donation out on a bus when the temperature outside is 105 and muggy (to put it bluntly you couldn't step outside and breath). When she stepped off the bus she fainted and fell down the stairs hit her head on the cement and couldn't remember her name. She is now in the hospital. What is the hottest temperature you can donate blood outside without it being dangerous?