4. 11. 2018 v 23:35, Bruce Mutton via Therion <therion@speleo.sk>:

It happens for me all the time, and I wipe with my hand, lick the display clean (yuk), or wash it in a stream or from my water bottle.

As wrote Marbach (in Alpine Caving Techniques http://speleo.lt/speleo/Knygos/Speleo/EN/Alpine%20Cave%20Techniques%20%5BEN%5D.pdf): 

His tongue is sometimes only the clean part of body of a caver.

m.