On Wednesday 3 March 1999, Wimbledon were about to play Sheffield Wednesday in a Premier League game. In the team coach on the way to the ground, Joe Kinnear, the Wimbledon manager, felt himself suddenly becoming very sweaty, unable to stop mopping his brow. One of his assistants asked if he was all right and he replied that he was fine, fine, just a bit of heartburn.

As he walked on to the pitch before kick-off, he began gulping for air and his throat felt funny. His chest was heaving and he could feel pins and needles in his left arm. "Fucking hell," he thought to himself. "What's going on?" He was having a heart attack, that's what was going on. The Sheffield Wednesday doctor examined him and called an ambulance. Joe was rushed to hospital, an oxygen mask on his face, where they gave him a clot buster. They told him the next hour would be vital, and asked him if there was anyone he wanted to ring. He thought, that's it, the game's up.

To make the next hour go as quickly as possible, he found himself counting the seconds backwards. At the same time, he was making vows in his head. If he got out of this, he'd change his life, be sensible, put football in proportion from now on.

Though it wasn't technically a heart attack, something similar seems to have happened to Gerard Houllier last Saturday. And at a similar age - Joe was 52, Houllier is 54. The stress of football management had got to them. Or had it?

When he had the heart attack, Joe was the second longest-serving manager in the Premier League. He didn't feel under stress, so he says. He was doing a brilliant job with Wimbledon, keeping them safely in the Premiership, getting them into three Cup semi-finals. The chairman and the players loved him. That evening, unbeknown to him, as he was otherwise occupied, the Dons won 2-1, making them fifth in the league - a position they seem unlikely to attain again. It wasn't just Joe who collapsed that night.

While the job itself was not getting him down, so he still maintains, he was clearly putting himself under stress during each game. You only had to see him screaming and shouting on the touchline. "Yeah, I did used to knacker my voice. On Mondays, I'd come into training still with a sore throat. But that was the only ill effect I can honestly say was a result of my work."

Which is a lie, or self-delusion. By the nature of his work, and the way he chose to do it, Joe was slowly killing himself. He was taking on too much, working stupidly long hours, the way all managers do. Almost every evening, after a long day, he was belting up and down motorways, watching other teams, looking at players. During the week, he never took proper meals, eating fry-ups in transport caffs, buying chips and burgers on the way home to scoff on his own in the early hours while watching games that his wife had videoed for him.

On Saturdays, after a game, win or lose, it was off to the West End for a late dinner of oysters, fillet steak and champagne.

During his playing career, when he was a slim, elegant full-back for Spurs and Eire, he weighed 11 stone. By the time of that Sheffield game, he was more than l5 stone. "OK, I'll admit it, I was 16 stone." Far too much for someone only 5ft 8in tall. Rival fans, watching him screaming on the touchline, would amuse themselves by shouting "Fat bastard". He didn't have a heart operation, which Houllier has had, but he was convalescing, on various diets and medications, for more than a year, during which time he gave up managing Wimbledon.

Yet who is to know if it was football that did it? We presume so, after what happened to Jock Stein, Barry Fry, Graeme Souness. If anything, the strains and pressures in football have grown worse over the past two years. Houllier had been talking about the problems of keeping 20 millionaires happy, which was a burden Joe didn't have to carry at Wimbledon. With a big squad, full of stars, as at Liverpool, there are always those who will hate you or cause trouble. When a club has spent millions, coming second is seen as a disaster. Your salary might be enormous, but so are the sacrifices.

On the other hand, a surgeon carries far more serious responsibilities, personally making life and death decisions. Nurses, teachers and social workers deal each day with more important, far-reaching problems than sucking a pencil and filling in a team sheet. It's only a game, after all. But inside the game, it doesn't seem like a game. It's life and the whole damn thing. When a surgeon is at work, he is basically on his own, relying on his own skills and experience. The patient just lies there, counting the seconds, promising to be a good boy from now on.

One of the unusual aspects of being a football manager is that, at the most vital time, during those 90 minutes, he can do virtually nothing. It's out of his hands. No wonder they scream and shout. Even with those who normally appear placid, such as Houllier or Wenger, you can see the strain, the inner contortions. Letting it all out, as Joe used to do, is perhaps as good a release as any.

And as Joe still does. Not, perhaps, as manically as he did before, but he's now back on the touchline, as manager of Luton. And doing pretty well, currently heading the Third Division.

The last time I saw him, he had put on a bit of weight again and was having the odd drink. Nothing like the old days, but the mad passion for the game is back. Humans have only experience of being human. And with most of us, it doesn't seem to teach us very much.