Using enough yarn to go around Singapore more than twice, a group of knitting fans have brought warmth to others.

With almost 500km of yarn, members of Singapore Facebook group Yarns Spree made more than 2,500 beanies, scarves, mittens and booties for children in northern Thailand, where temperatures can dip to as low as freezing point in mountainous villages.

Financial planner Amanda Seet set up the community last year to organise group buys or "sprees" of affordable yarn from overseas websites.

But in the middle of this year, the 40-year-old heard about charity group Radion International's call to help underprivileged children in northern Thailand's Phetchabun province. "I realised that since I already have this (Yarns Spree) group, they would probably be keen to contribute," she said.

She got in touch with the charity in July and learnt that they would have to get the items ready by September. She posted about it on the group's Facebook page, and about 150 of the about 500 members chipped in.

"Some said that they were busy but I told them, 'Even if you can only do one, it means one more person can get warm,'" said Ms Seet.

It can take from 20 minutes to three days to make one item, depending on how fast the knitter or crocheter is, and how complicated the design is. Some members also roped in their families. Mr Scott Ryktarsyk, 52, got involved thanks to his wife, who knits as a hobby.

"She said it was for charity so I thought, 'Sure, let's do it'," said Mr Ryktarsyk, a regional project engineer for a flavour and fragrance company.

"I travel a lot for work and ended up knitting a lot on the plane - which got some strange looks!"

Radion International is collecting winter clothing, medical aid and other supplies for rural communities in Phetchabun.

"We have never (before) received so many items of winter wear for the children," said Radion International founder and executive director Eugene Wee.

"We look forward to working (more) with Yarns Spree and more like-minded groups."

One young contributor is looking forward to doing more.

Jaylen Cheong, nine, crocheted two hats - sometimes as a break from homework.

"It's a bit of fun, and sometimes when my hand is tired from writing, I will take a break and crochet," said the Primary 3 pupil.

"I'm trying to do a scarf next."

His mother, housewife Shirley Lim, 37, has been knitting and crocheting for years.

She said: "He saw me doing it and then he got interested. It's good because it also keeps him off the TV, gadgets and so on."

Jaylen added: "I like that I can use my project to give stuff to those who need it more."