He visited villages in the African nation of Swaziland for two years from 2011 till last year looking for orphans and children in extreme poverty.
They lived in huts made of mud, sticks and weathered leaf roofs that left them freezing when the temperature dropped to almost 10 deg C when night fell.
Mr Tan Kah Ching is a Singaporean who used to make about $8,000 as a librarian at The National University of Singapore, but gave up his career to fulfil what he called "an urge to see a change in the world".
The 48-year-old now lives on an allowance of $60 monthly as a full-time volunteer at the African Children Care Centre (ACC) in Swaziland.
He told The New Paper: "I could never have been happier with where I am now."
There are 11 other volunteers in the centre, with most from Taiwan, Hong Kong and Malaysia.
Mr Tan and the director of ACC Swaziland, Taiwanese Cheng Shu-Ying, are in Singapore for the "With Love, We Are Here 2014: Africa ACC 10th Anniversary Concert" with 18 children from Swaziland and four from Malawi.
Most of the children at ACC are orphans, but some were left at the centre because their parents were unable to look after them. The ACC is a humanitarian foundation founded in 2005 and it seeks to provide shelter, food, education and care to orphans all over Africa.
ACC also has centres in Lesotho, Mozambique and Namibia.
According to Mr Tan, many births are not reported to the authorities and it is therefore impossible to know exactly how many orphans there are in the country.
He said: "All I know is we are only helping a small percentage that is equivalent to a speck of dust." ACC is now home to about 87 children in Swaziland, aged between three and 15.
The bachelor, who used to live alone in a flat in Bedok, said he was inspired by the late Mother Teresa's generosity and kindness.
He said: "I was paying off hospital bills for my late parents. After I was done, I had no further obligations so I decided it was the right time to go."
Mr Tan, then 45, was not in a relationship.
After looking at the ACC website back in 2011, he decided to join the association.
When he was in Swaziland, there was an incident that made a big impact on Mr Tan.
He said: "We went to a small village and met a father and son who lived next to the road. The boy, who was seven, started to miss class because of his family's situation. It was difficult to gain their trust because most of the time they would question, 'Why should I trust someone with a different skin colour?'"
'JOY AND VALUE'
The Director of ACC Swaziland, Mrs Cheng, told TNP: "People think that we're helping them, but in truth, they're the ones adding joy and value to our lives.
"She first visited Swaziland in 2007, and in 2011, the first batch of about 20 kids came to the centre.
She said: "My friends always ask me if I'm tired, as we don't have holidays nor much money. But I just tell them that helping the children is enough. This is now my life and how can you be bored of life?"
Mr Tan hopes for more people to come forward to help these children.
He said: "In Singapore, we all grew up putting practicality as priority in our careers and it's not wrong.
"But we should try to be mindful of the things we need and the things we want.
"Give what you can, take slow baby steps and you'll understand the joy that comes with living for others."
This article was first published on August 16, 2014.
Get The New Paper for more stories.