Looking for a YA book that I read around 1996 that had a sci fi setting. The humans had to wear sealed glass helmets which made them sweat, and the sweat would pool in the helmet. They sucked on salt sticks to replace the salt lost in sweat. I also remember the cover of the edition: it had a drawn color image of the female main character and in the illustration she had a really prominent filtrum!
Lost Classics of Teen Lit: Name That Book! 