When I was a kid I used to look after a bunch a remote, automated air monitoring stations located in and around the rural and back country places of Alberta. They were usually housed in those little industrial ATCO trailers and sampled ambient levels of H2S, sulphate compounds and other industrial pollutants. They also recorded wind speed and direction and none of 'em ever worked. I literally lived in a half ton truck driving from one end of the province to the other downloading the data - there was no internet then - and struggling with the infernal instruments to make them work.
The air analyzers were fed a constant stream of outside air by tiny compressors that drew the air in and pushed it through the analyzers - and then vented back outside. I got called to a station down in BW Bandy country near Bodo, AB. It's flat as a board there and it used to be home to one of my most hated stations. The fuggin machines there NEVER worked and I was in there at least three times a month fixing the damned things. (This was all super-high tech stuff back in the 90's).
In any event I showed up to see what it was THIS time and found all the analyzer off line. Typical. So I started trouble shooting the plumbing and soon found that there was no airflow or suction at the air intake. So I traced it back to the exhaust and knew it had to be frozen or bunged up - so I started slapping the plastic line against a counter top to break the ice inside the line and blow it out. No dice. I wrapped my hands around it, trying to warm it up and maybe melt some of the ice to blow it out. Forget it! In consternation I looked down that rubber hose - but couldn't see anything. WTF? Idly I slapped the line in my hand as I thought - and the slug of ice let go and shot me right in the palm - and I did the same hideous Dance Of Pain that kid in the GIF did! Jeez, that hurt!
After the pain subsided I thought back and realized that I had been looking straight down the bore of that sample line and had it let go then... I probably would have lost an eye. One seldom thinks about it - but there are times when Darwin and Murphy show incredible restraint.