'Lecture Demonstration'' is a short story by Hal Clement. It was first published in Astounding: The John W Campbell Memorial Anthology in 1973.
Dr LaVerne, a teacher with the College, takes a party of Mesklinite students on a geological expedition. Whilst examining a layer of rock, it collapses. Teacher and students fall into a cavern. They are unable to climb out; the limiting factor is time as the teacher is enclosed in a suit with a finite oxygen supply.
The students and teacher discuss various possibilities until the realise that they can raise the melting point of the surrounding ammonia 'snow' to the point where it soldifies. They climb out to safety.
Improving Students' Perceptions of Benefits of Science Demonstrations and Content Mastery in a Large-Enrollment Chemistry Lecture Demonstration Course for Nonscience Majors
May 01, 2007; A large enrollment, instructor-centered chemistry course taught with science demonstrations was transformed into one that was...