Together, the pair helped create the first Apple computer after working in Silicon Valley.
Apple then went on to become the most valuable company on the planet.
More recently, Wozniak was among a number of prominent signatories – alongside the likes of Tesla owner Elon Musk – in a letter calling for a pause in artificial intelligence (AI) development.
He told the BBC that AI regulation was vital during an interview back in 2023.
He said: “AI is so intelligent it’s open to the bad players, the ones that want to trick you about who they are.”
However, he added that regulation had to be made correctly.
Wozniak concluded: “I think the forces that drive for money usually win out, which is sort of sad.”
On Wednesday, Wozniak was delivering a speech and told his wife he was “feeling strange” after it had concluded.
His wife immediately raised the alarm after being told his symptoms, celebrity news site TMZ said.
The businessman initially refused to go to the hospital – but on the insistence of his wife eventually went.
He underwent tests while aboard his private jet, with medics checking him to see if required further treatment in the US.
According to Reforma, he is currently still in hospital in a “stable” condition.