She touched his pale, lifeless feet so gently and so intimately that I quickly turned away, mortified in case caught in my intrusive sideways look. The sun had that late surge of intense heat that often comes with autumn in the south of France.

His naked feet were the only uncovered part of the man; delicate, rather beautiful objects, on an elongated and padded wheelchair – more stretcher than chair. And so she smoothed and anointed them in the fierce glare.

With her auburn hair falling and covering the side of her face, her Breton T-shirt pinpointing the sharp shoulder bones and the jeans her skinny legs, I took her for a daughter.

Only later when I looked into the tense, overwhelmingly lost and lined face, did I realise she must be his wife.

Of course I was aware when I came to this clinic for heart and lung rehab that there was a separate ward for those in a vegetative or pauci-relational state – a state of minimal consciousness where simple instructions can be followed.

And I wondered how this extraordinary work would fit in with all the walking wounded I would now march along with.

My knowledge of such souls comes in the main from books and films such as the searing Diving Bell and the Butterfly, the true story of Elle editor Jean-Dominique Bauby, who suffered a massive stroke that left him with locked-in syndrome. His suffering and loss were painfully described by blinking his left eyelid to "write" of past and present.

I once though interviewed a young woman left in a coma for months after an accident in her teens. In her new hesitant voice with its scrambled memories she told me of listening to the discussion of doctors as they told her mother it was time to switch off.

"I was screaming, 'It’s me, it’s me … I’m here,'" she said as her mother wept still at the recollection. Only her mother asking for longer meant a twitch of her body, somehow willed into being by her locked brain, saved her.

So when I first passed the man as he lay trapped in the shade at the side of our outdoor fitness circuit, I smiled in the direction of his impassive face and whispered "bonjour".

Of course there was no flicker across the sun-glassed eyes under the cap pulled over the forehead. No movement in the shoulders swaddled in blankets.

He was often there in the days that followed and I began to think he was the only one who existed beyond the doors marked "Interdit" (no entry) at the end of my corridor.

But then I saw two more like him, only women, who were wheeled to pleasant spots around the grounds by nurses or family.

Like him they lay inert and protected by hat and covers against the afternoon heat. They existed on a level detached from all of us who trudged along feeling every breath we drew. Every breath, I now realise writing this, that told us we were still here, still trying.

Always their minders talked off and on to them or read from books, often gently touching hand or face. I never saw a response to them in my passing, but staff and family never stopped their attempts at saying: "I’m here, I’m here," in case, I suppose, the one inside was crying too: "I’m here. It’s me. It’s me."

Today, a weekend day, where time hangs heavy and thoughts run wild, I sat on a bench immersed in a book as a hot wind blew paper-dry leaves in a cacophony of sound around me.

I was aware of only that sound until a raucous series of sounds roused me out of my heat stupor. For a moment the repetitive, one-note semi words were similar to responses in the Latin mass or a Gregorian chant. And yet they also had the harshness of an imam’s call.

I turned to the side following them, and there, by a bench not far away, having slipped silently alongside, was the man to whom I whispered "bonjour".

He lay as still as a statue while these sounds, sentences, erupted from him.

Sitting on the bench, head bowed before him, the woman, the wife, was stroking those poor feet. Her whispers to him grew more intense as he howled to the sky.

Perhaps she found meaning in them. It surely is not fanciful with all we now know to think it was an awakening of some kind, though evidence suggests otherwise.

I returned to my book, embarrassed to have witnessed her quiet anguish and kept my head down, as did she, until I saw her pushing him away, back into the second-floor corridor.

No doubt tomorrow he will be there again as we huff and puff around the circuit. As it’s a weekday, a nurse will sit by his side, either reading aloud or perhaps describing what is happening.

I have never heard sounds from him in the company of his carers; only as he was touched by loving hands in remembrance today.

In a day or two I will drive away from here. And in time I will forget the suffering behind these doors.

I won’t forget that woman.