Explorer I, Explorer 2 and Subbie Test Conditions

[FryeGuy]

Hey all, I suppose this is a technical question...

Not long ago, I read an article about adventurer Mike Horn - who is, in addition to an adventurer, a Panerai ambassador (see below for link to Hodinkee for article). It mentions that his Panerai is special because it is freeze resistant to the North Pole in winter (whereas digital watch crystal would freeze). My question is, how special is this Panerai, really? What are the lowest and highest temperatures Explorer 1, Explorer 2 and Submariner can withstand without problem? (And if anyone knows that same answer for the deepsea, awesome).

http://www.hodinkee.com/blog/2011/10...wore-a-pa.html