It started with aheadacheanddizzinessduring a Monday-morning training session in January 2021.

First, Daley chalked it up to a mild concussion he had experienced while diving several weeks earlier.

But with his headache still present the next day, he took a rapid test forCOVID-19just in case.

Tom Daley

Martin Rickett/PA Images via Getty Images

He took anotherrapid test, and again it came back negative.

Although thesore throatfaded within a couple of hours, worrying new symptoms began that night.

Daley had a very high fever, and alternated between severe chills and burning up.

My teeth chattered so hard and my skull ached.

I hadnt felt that bad since I had pneumonia.

He also haddebilitating dizzy spells.

As I went to bed that night, I was nervous, Daley recalls.

I even checked that Lance would know what he needed to do if I stopped breathing.

I honestly felt like I might die.

He took painkillers and planned to see a doctor the following day.

At this point, Daley still didn’t believe it was COVID-19.

For the third time, he took a rapid test that came backnegative.

He also thought it was unlikely he had beenexposed to the virus, given how careful he was.

“I wore my mask and washed my hands religiously.

I had not been anywhere else.

I couldnt even say two words without coughing my guts up.”

(The couple did not have a car.)

Daley ordered anat-home test kit, but his condition only deteriorated further while he waited.

By then my bones were aching all over and I had a hacking cough.

My lungs felt pressurized, as if they had sacks of rice around them, he writes.

COVID suddenly seemed a very real possibility.

Within eight hours, Daley’sPCR testresults came back positive.

Though Daley’s condition actually seemed to improve for a few days, hiscoughand other symptoms soon returned.

This time, the NHS sent a paramedic to evaluate him.

I understood how quickly things could potentially go downhill," Daley writes.

He was afraid he might die.

I was really terrified.

A chest X-ray revealed loads of blotches on Daley’s lungs.

Doctors gave him supplemental oxygen and monitored his vitals.

After about 10 hours, Daley’s oxygen levels stabilized, and he was discharged.

Three days after getting home from the hospital, Daley finally started feeling some relief.

The overwhelming feeling was a sense of relief that it was finally over.

The diver’s recovery period sidelined him from Olympics training for the entire first quarter of 2021.

He estimates he is working with about a 5% reduction in his cardiovascular fitness.