The three-year-old grandson of Norman Kember keeps asking when he will return from Iraq, the wife of the kidnapped peace activist has told al-Jazeera.
In a new appeal on the Arab TV channel, Pat Kember said she was "very worried" about the 74-year-old Briton's health.
Mr Kember, from Pinner, north London, was seized in Baghdad on 26 November, with two Canadians and an American.
Ben hopes he will come home, go to the bedroom, "wear his pyjamas... and start snoring", Mrs Kember said.
Mr Kember, James Loney, 41, Harmeet Singh Sooden, 32, and American Tom Fox, 54, had travelled to Iraq as a gesture of solidarity with Christian Peacemaker team, a Canadian-based international peace organisation.
Mr Kember was last seen in a video aired on al-Jazeera on 8 December, blindfolded and with his hands tied, but there has been no news from his captors since then.
The four men were seized by a group calling itself the Swords of Truth.
It had demanded the release of all Iraqi prisoners detained by British and American forces by 10 December - a call which has not been met.
Mrs Kember re-iterated that her husband was a "peaceful man" who wanted to help the Iraqi people.
TIMELINE OF ABDUCTION
26 November: Norman Kember is reportedly abducted along with three other peace workers
30 November: A video showing the captured peace workers is shown by the previously unknown militant group Swords of Truth Brigade
1 December: Anti-war campaigner Anas Altikriti flies to Iraq to plead for Mr Kember's life
4 December: Mr Kember's wife Patricia makes a plea for her husband
11 December: The original deadline from Mr Kember's captors passes
24 December: Family start to issue appeals in Iraqi radio and newspaper adverts
24 December: Muslim Association of Britain make appeal on al-Jazeera broadcast
"I know that Norman would like to continue charity work in the future," she said.
"But I want him to return home soon. We need him here, all of his friends and family."
Mrs Kember said her husband did not have his medicine with him.
"I hope he is well," she added. "We are all very sad here."
Mrs Kember said their grandson Ben "keeps asking" when his grandfather will come back home.
"I would like to finish with what little Ben has said," she said.
"My grandpa will come home. He will knock on the door and then rush to the bedroom, wear his pyjamas, sleep and start snoring."
Mrs Kember's appearance on al-Jazeera was the latest appeal from the hostages' families.
She previously appeared on the channel on 4 December, saying that her husband and his friends were allies of Iraq and had gone there to make it "a safer place".
A series of radio and newspaper adverts were issued in Iraq over the Christmas period and the Muslim Association of Britain has also been working to secure their release.
The Foreign Office said it had no new information about Mr Kember.