Shortly afterwards, says the 27-year-old Saudi, "I was almost dead".
Hussein, who had often visited his father's bedside in his last days, was admitted to intensive care in a hospital in Dhahran, in the Eastern Province oil heartland of Saudi Arabia.
Then his brother, Abdullah, and later his sister, Hanan, fell ill, obtaining treatment in hospitals in the nearby oasis district of al-Ahsa.
Their father Mohammed, it has since emerged, was probably a victim of what doctors believe was novel coronavirus, the new SARS-like disease that first emerged in the Gulf last year and has gone on to claim 18 lives, nine of them in the kingdom.
There is international concern, because it was a virus from the same family of pathogens that triggered the outbreak of Severe Acute Respiratory Syndrome (SARS) that swept the world after starting in Asia in 2003 and killed 775 people.
Some of the cases of the new virus were in Britain and France, among them people who had recently travelled from the Middle East. A total of 34 cases worldwide have been confirmed by blood tests so far.
"My temperature was really high, my blood oxygen levels were very low. I was so tired I couldn't walk for days and any kind of activity made me cough," said Hussein, a PhD student who studies in Canada. To avoid spreading infection, he wore a green face mask.
World Health Organisation (WHO) experts this week visited Ahsa, a sleepy oasis of around a million people, to work with Saudi authorities in investigating the latest outbreak.
Much of the attention has focused on the private al-Moosa General Hospital in Hofuf, Ahsa's main town, where many of those infected, including Mohammed al-Sheikh, were treated in the intensive care unit.
A senior WHO official said on Sunday it appeared likely that the virus could be passed between people in close contact.
WHO Assistant Director-General Keiji Fukuda said, however, that there was no evidence so far that the virus was able to sustain "generalised transmission in communities", a scenario that would raise the spectre of a pandemic.
A public health expert, who declined to be identified due to the sensitivity of the matter, said "close contact" in this context meant being in the same small, enclosed space with an infected person for a prolonged period of time.
Mohammed al-Sheikh, who suffered from diabetes and had been admitted to hospital with a high fever and low blood sugar never knew what had infected him. He lost consciousness two days before he died.
"The doctors said they didn't know what was wrong," said Hussein. "During his first two days in intensive care he could talk and eat by himself and go to the washroom. But then it got worse. He was on the highest level of oxygen and they had to drug him. He left without saying goodbye," he said, referring to his death.
In the wake of rumours about the extent of the virus in Ahsa last week, some families of people who were hospitalised said they had been asked by authorities not to speak to media.
Separated from the big cities of Riyadh and Dammam by large stretches of desert, Ahsa is a pretty area famous for its date farms. Drive through its dusty villages and goats appear grazing beneath the palm fronds. Between the trees jut pale rocky outcrops carved by the elements into outlandish shapes.
CALAMITY OF A FATHER'S DEATH
There was little sign in the al-Moosa General Hospital's reception area late on Saturday that it was at the centre of a global health concern.
Visitors, doctors and nurses hurried down the corridors. Two women in black hijab waited with their babies outside a door marked "vaccination room".
Hussein al-Sheikh said he believed his father contracted novel coronavirus in the hospital's intensive care unit and that he then caught it there himself during the hours he spent visiting his father in the days before he died on April 15.
But Malek al-Moosa, the hospital's general manager, denied this suggestion and said he believed the patients were in fact exposed to a common source of the virus outside Moosa General Hospital.
Fukukda of the WHO said it was not yet clear how the virus was transmitted.
Of the four members of the Sheikh family who fell sick, only one, Abdullah al-Sheikh, 33, has so far been tested positive for novel coronavirus.
Samples from Mohammed, Hussein and Hanan are still being tested but Moosa said it was likely that they also had the virus.
A poster-sized portrait of Mohammed al-Sheikh, a 56-year-old former employee of the national oil company Saudi Aramco, is displayed in the Sheikh family's reception room, where three of his 10 children sat to describe what they call the "calamity" that has hit their family.
"Our father's dream was that we should all live in one house with a big garden. He had started building it and finished almost 50 percent. This is just killing us," said Hussein.