MAYBE it was altitude sickness that struck Shane Monahan at the start of the second-half.
The powerhouse Irish wing took a knee and vomited right in front of The Shed, delaying the resumption of this resounding victory.
Former Leinster academy man Monahan could find no obvious answer for his brief ailment, and he certainly did not feel concussed.
Perhaps the only explanation then is that he was simply overcome by the dizzying heights of his increasingly-impressive Kingsholm career.
His two tries in the final five minutes of the first-half totally transformed this contest.
One-dimensional Gloucester laboured for the first half-hour, battling for fluency and struggling to find the guile to generate penetrating quick ball.
Then up stepped Monahan with two startling scores, and in a flash, it was game over – and Gloucester put one foot in the Amlin Challenge Cup quarter-finals.
Two more tries after the break and that funny turn, capped one of the finest days of Monahan's career, the 25-year-old gaining just reward for constant industry and imagination.
When he arrived at Gloucester in the summer after a year in the Championship with Rotherham, he freely admitted he had a job on his hands just to command time on the field.
Now he is among Nigel Davies' most important strike options.
At times he offers himself up for selfless tight driving work like an extra flank forward.
And then in an instant he can cut the kind of intelligent line that brought his first try on Saturday.
Mike Tindall offloaded out of the back of a tackle, Sione Kalamafoni powered through the line and dragged about three flailing defenders with him.
At the ruck Jimmy Cowan crabbed left to right, delaying just long enough for Monahan to cut off the blindside wing and exploit the fact Irish had failed to cover the fringes properly.
Searing away, Monahan arced back out to the left wing, and outgunned full-back Tom Homer for the try to turn the game on its head.
Freddie Burns slotted his third penalty of the half shortly afterwards, and from the restart Gloucester struck again.
Irish dropped the ball short and wide, hoping to catch Gloucester napping.
All they caught was a whack in the chops from Kalamafoni though, who claimed the high ball, spun away from two chasers, and careered down the touchline.
The Tongan monster's physicality is only increased by his pace, and he powered clear – before drawing Homer and flipping inside to the lurking Monahan.
The gleeful Irishman raced onto the ideal pass, and cantered home for try number two.
Burns converted for half-time, and what could have been a circumspect turnaround was suddenly a situation of complete control.
After the restart, just when Gloucester thought they had butchered a series of penalties in the Irish 22, Rob Cook struck.
Shane Geraghty's poor clearance allowed the impressive Gloucester full-back a chance to counter – and the visiting defence evaporated.
The former Cornish Pirate bisected the ragged Irish kick-chase line, racing straight through centre-field and under the posts.
Charlie Sharples then produced a buccaneering break from his own half, scything in off the right wing, to set up the bonus-point try.
As Gloucester set camp in the Irish 22, the ball was flung wide at pace – and who else was there but Monahan, to claim his hat-trick.
Burns then threw a neat pass over the top for replacement centre Tim Molenaar, who powered up, and then Monahan nipped round the ruck for his fourth.
Irish had their half-chances, but Brian Smith's side are in trouble.
Nothing is working for them, and it is clear that the more that fails, the more they force the issue and plumb greater depths.
The Reading-based men need to break their vicious circle, as they clearly face a straight relegation fight with London Welsh and Sale Sharks in the Premiership basement in the second half of the season.
No such worries for Gloucester though, who completed the romp – and a second win in as many weeks over the Exiles – with a smartly-taken score from replacement scrum-half Dan Robson.
Jim Hamilton cut the line in the 13 channel – yes, you read that right – and Gloucester broke into the Irish half.
Loosehead prop Nick Wood stepped up at first receiver – again, no need to rub your eyes – and produced a superlative defence-drawing pass to set Robson away.
The impish half-back jinked in to out, terrorising the Irish cover, and raced home for try number six.
All too easy – but Gloucester made it that way, so huge credit to them for that.
Christmas clashes against Exeter and Leicester next: Gloucester boast masses of momentum, but must be wary of the steep climb in intensity ahead.
Two stubborn, gritty and gnarled opponents will provide an intriguing barometer of just how far Gloucester have come under Nigel Davies this term.
LONDON IRISH: T Homer, T Ojo (C Gaston, 60), S Shingler (D Danaher, 73), G Armitage, A Watson (S Tagicakibau, 62), S Geraghty, D Allinson (J Moates, 52), M Lahiff (J Yanuyanutawa, 41), D Paice (S Lawson, 41), H Aulika (L Halavatu, 41), J Sandford (M Garvey, 52), B Evans (capt), K Low, J Gibson, A Gray.
YELLOW CARDS, GLOUCESTER: James (46), Britton (78).
REFEREE: N Paterson (SCO).