Howard Jacobson: I lay on my sun bed and enjoyed the most perfect reading experience you can imagine

It's so hot out there that if I quit the shade for more than 10 seconds I will grow a melanoma

Discovered a new pleasure: lying on the beach reading writers describing lying on the beach. It's awkward reading on the beach if you're not sufficiently flexuous to get the right degree of shoulderly twist to read the words, or the right degree of cranial lift to turn the page, and if you don't have the bodily or astronomical savvy to work out how to get the sun on the book but not on you. But that's the joy of reading about someone who manages it no better.

Reading is never more satisfying than when you feel allied with a writer in discomfort. So lying in agony on a beach with a book that excels at evoking the agonies of lying on a beach is the most perfect reading experience of all.

Simon Gray got me through the holiday from which I've just returned, or least he got me through the beach part of it. I'd been saving The Last Cigarette, the third volume of his The Smoking Diaries, to take away with me, knowing that his masterfully comic dyspepsia would be just the tonic in the heat. But I hadn't realised that he too would be on holiday in it some of the time, so that I would be able to lie there, so to speak, and let him fulminate for both of us.

"Listen to this," I say to my wife, who is lying next to me. Though she has a back injury, and no more wants to be exposed to the sun we've just paid thousands of pounds to lie in than I do, she still manages to find a graceful way of curling up and reading.

Women, of course, have more adaptable bodies than men. Something, presumably, to do with childbirth. Come the hour, they have to be able to bend themselves into positions impossible for a man. Not that we're here to have a baby. We're just here to escape the sun. And read. Which sometimes mean reading to each other.

"Listen to this," I say, interrupting her and Philip Roth. I am not entirely happy, I have to confess, about her lying there with Philip Roth. The one consolation is that he doesn't find life funny any more, so at least I don't have to listen to her laughing. It's not quite a rule between us but it's understood that I would rather she didn't laugh at another man's prose – laughter in a woman denoting erotic appreciation – particularly when she's in the prone or semi-prone position.

For some reason we make an exception of Simon Gray. This is not because I don't find him masculinely threatening – he is, actually – but because he is not a marriage-breaking writer, as Roth most definitely is. I can only explain that by saying that Simon Gray doesn't raise the ire of either sex against the other. On the stage sometimes, maybe, in earlier days, but in his diaries, no.

The passage I want to read aloud to my wife, who has already read The Last Cigarette but doesn't mind hearing it again, describes the diarist lying on a plastic bed on a cement beach in Greece, surrounded by bodies he doesn't find attractive ("little strips of material between their legs"), listening to voices he loathes ("voices you could grate cheese on"), a cigarette jammed into his mouth, "the sun pouring through my straw hat like a molten headache".

A wonderful image, a molten headache, partly because it enacts the condition of becoming molten which is continuous – the sun continuing to pour, the hat continuing to provide no adequate protection, the head continuing to melt. So you can go on reading and rereading the sentence, the ache getting worse with every read.

Indeed, when my wife wonders why I haven't interrupted her with another favourite phrase or paragraph for at least 15 minutes I have to tell her that I'm still on the molten headache which is beginning to pour like liquefying gold out of my own skull now.

That is partly the actual sun's fault as well as Simon Gray's. It has crept under the umbrella while I've been busy laughing but I can't work out which side it's coming in from. There are diamond-shaped patches of intense light on my arms and chest, caused partly by gaps in the material of the umbrella. I could climb off my bed to fix them, and at the same time work out where the sun is, but it's so hot out there that if I quit the shade for more than 10 seconds I will grow a melanoma.

There is also, to be considered, the difficulty of rising from a sun bed at all at my age. How to get the leverage? Apply too much force to the bed and it sinks into the sand, grab hold of the umbrella pole with your weight and you'll topple it – and that's a melanoma each in the time it takes you to put it up again – which leaves only your wife's shoulder to reach out and press down on, and she won't appreciate that given her injury and the intense absorption of her concentration on Philip Roth's Exit Ghost, which has patently reached a crisis, that's if there's anything in late Philip Roth that isn't crisis.

It's crisis time for Simon Gray, too. Best friends dead and dying, his own tobacco health no great shakes, the body reluctant and unwieldy – for which, as I try covering up the triangles of killer light, first with what's left of a sandwich I've been eating, then with The Last Cigarette itself (a manoeuvre that involves balancing it on my ankles and bending double to read the words), I have considerable fellow feeling. "Not exactly serenity, more a gentle vacancy of spirit," Gray writes, describing that "suspended mood when you know there's much to worry about but you can't remember what it is". All we have to look forward to now – a gentle vacancy of spirit, which is a great thought because it admits its impossibility, or at least its fleetingness, in the utterance.

But no, there is something gentler about this volume of Gray's diaries. No dilution of the rage, no minimising of despair, and certainly no false comfort – but a great suffusion of warmth, especially in the man-to-man, eyeball to eyeball descriptions of his friends Alan Bates, Ian MacKillop, Harold Pinter. Astute portraits these, but infinitely touching, too, in their acknowledgement of love. You have to be of an age to write like this. It's not only the wit but the time-dyed tenderness a younger man could never manage. I console myself with that thought as I lie dying in the sun.