Piers Morgan spoke out on Good Morning Britain on Monday, after viewers apparently tweeted in to the show "concerned" about him.
Susanna Reid was told by her co-presenter that people were tweeting in, saying he looked unwell and were wondering what was wrong.
Piers laughed off some of the comments, as he read them out and they appeared to mock his appearance.
But Piers had been unwell, he confirmed, after a little too much sun in the UK heatwave.
His trip to the golf course led to him suffering with severe sunstroke and heat exhaustion.
As a result, a poorly Piers was left in bed all weekend "unable to breathe" or even move.
He said on the show: "I woke up on Saturday morning and suddenly went 'wooo, wooo'.
"I hadn't had a single thing to drink - I had heat exhaustion. I spent two days in bed. I basically couldn't walk, couldn't breathe. I could barely talk.
"It was a utopia for my critics really. Heat exhaustion is actually quite unpleasant, I've discovered. I was very tired. I just slept it off."
Piers confessed he might not have fully recovered, before returning to work on Monday - only to be faced with remarks from viewers.
Susanna repeatedly asked how he was, clearly having spoken to him across the weekend.
Some of the comments Piers read included one where a viewer said his face looked "bloated".
Piers decided to address his sickness with fans, having confessed earlier on in the show that he couldn't walk or breathe all weekend.
He quipped: "Getting a few concerned thoughts on Twitter, am I okay, I'm looking ill. Keith, 'are you alright mate? Face bloated, pinhead eyes, faltering voice, get well soon'."
He began laughing hysterically, before adding: "Somebody else said Piers is unwell. I spent all weekend in bed with heat exhaustion, I was playing golf.
"I probably haven't completely recovered, but you know what? You dig deep and you battle on."
Susanna mocked his "bravery" over still working despite not being well.
She then asked how he was, to which he replied: "Not great, but I'm certainly helped enormously by the touching concern of viewers.
"It always helps actually."
Good Morning Britain airs weekdays at 6am on ITV.
