I guess it's possible; but the weapon supposedly freezes things near instantaneous, which might be a problem with helium because of its low heat capacity. Things like us humans have mostly water composition, so that might take a while!
If they had that technology, it might be easier to...
The http://crysis.wikia.com/wiki/Weapons#Aliens" - are they theoretically possible?
The weapon "Molecular Arrestor" is basically a freeze ray, is this thermodynamically possible? Freezing something would require removing energy - how something have its energy removed that rapidly makes it...