An insult to someone's intelligence or ability, or describing an individual who is struggling to keep up with the rest of the pack
. A 'cold shot' refers to a steam-catapult launch from an aircraft carrier when the steam pressure is too low for the launch weight of the aircraft; on reaching the end of the deck, the aircraft is going too slowly for safe flight and may drop dramatically, or even (in extreme cases) ditch. If ditching is avoided, there follows an agonisingly slow climb away with the handle jammed forward
and all the gauges pegged
in a desperate attempt to gain height and speed.