SD card Specifications

Does anyone know what the altitude/temperature limitations (if any) are for SD cards? I have a potential application where I would like to use one up to 50k ft if possible. I've tried Google but didn't find anything. I'm currently using a flashdisk/pcmcia for this application but would like to adapt to an SD card.

Must admit to complete ignorance. Have you contacted any SD manufacturer's support either by phone or online?

Yes - I was able to find the temperature limits: -25c to +85C.