Hume recoiled and wanted to look away, but his eyes remained transfixed on the screen in front of him.
The 33-year-old did not need to be told the stricken Hull midfielder was in serious trouble as he lay shaking on the pitch at Stamford Bridge.
Eight years ago while playing for Barnsley, Hume fractured his skull during a frenzied South Yorkshire derby against Sheffield United.
He knew instantly Mason was in a very bad way on Sunday afternoon.
“It was the way he landed, straight-legged on the turf,” said the Canada international. “Normally you’d crumble in a heap, but he just landed and then fell forward.
“And then there was the reaction, especially from Michael Dawson. It didn’t look good at all.”
Ryan Mason suffered a fractured skull after a clash with Gary Cahill
Ryan Mason required nine minutes of treatment during Hull's 2-0 defeat to Chelsea
November 8, 2008 was the day Hume could have died. An elbow from Blades defender Chris Morgan thudded into the side of his head knocking him out cold.
Hume suffered a fracture and internal bleeding – only no one knew how bad his injuries were at the time.
It is less than a decade ago but we live in a more enlightened era now with clear medical guidelines to follow for head injuries.
While Mason was whisked to a west London hospital for surgery after being carefully carried off the pitch, Hume simply went home and fell asleep.
“I was sent home with suspected concussion,” says Hume. “I didn’t go to hospital until the following day.
“Within a couple of months, the protocols changed and they started sending people directly to hospital for a check-up.
Premier League and Football League clubs send best wishes to Ryan Mason
Mon, January 23, 2017
Premier League and Football League clubs have been quick to send their best wishes to Ryan Mason after the Hull City midfielder suffered a fractured skull against Chelsea
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Football clubs all over the country have sent best wishes to Hull City midfielder Ryan Mason
“So in one sense, Ryan was lucky because he was in the right environment. He was probably inside a hospital getting examined inside an hour. They caught it early.
“I don’t know the extent of his injuries but he’s in the best possible place. And the fact the incident happened in a high-profile match which was being shown live on telly means he was always going to get the best possible treatment.”
Hume still shudders when reliving his brush with mortality.
“I don’t know how close I was to dying but it was a lot closer than it should have been,” he said.
“The worst thing to do at a time like that is sleep – and I slept like a baby that Saturday night because we did not know the extent of my problem.
“The following day, I couldn’t string sentences together and started talking gibberish. That’s when I was rushed to hospital.
Iain Hume went on to enjoy a fine career
“Fortunately a scenario like that wouldn’t happen today.”
Hume, who still sports an 18-inch scar the shape of a horseshoe on his skull, was in hospital for seven days. He didn’t play again that season but was back in action for the start of the 2009-10 campaign. He hopes and believes Mason will eventually make his own comeback.
“They kept my blood pressure down for three or four weeks while the scars healed but I was running again just after Christmas under close supervision from the physio,” said Hume, who has spent the past three seasons playing for Atletico de Kolkota in the Indian Super League and also played for Leicester, Tranmere and Preston.
“By March, I was feeling good and pestering the gaffer Simon Davey, begging him to let me get involved with the lads.
“In my first practice game, someone tried to chip me and instinctively, I jumped and headed the ball. He really ripped a strip off me for that, but that gave me confidence.
“I did not play a proper game until July and was back, challenging for high balls like I always had with no ill-effects.
“It’s no fun being out of action for eight months and there were spells when time really dragged, but when I think of what might have happened, it’s no time at all.”