Alfie Howell, four, and Libby Cotton, five, who both attend Whitehill Community Academy, Illingworth, have both had two heart operations since they were born.
The school took part in a Wear Red Day to support the Children’s Heart Unit at Leeds General Infirmary where they are being treated.
Alfie’s mum Anna Goldston, 30, from Halifax said that doctors spotted a hole in Alfie’s heart during a routine scan during pregnancy.
Investigations at the Children’s Heart Unit found that the main artery from his heart to his lungs constantly grew muscle mass, severely limiting his blood-flow.
He was operated on at five weeks and again at 18 months - he is on the waiting list for what doctors hope will be his final operation.
Anna said: “It’s not something they can ever repair, but the procedures help to give Alfie a better quality of life.
“He’s doing really well - he loves reading, he loves maths - he’s won the prize in school this week for his maths.
“He loves school - he’s like any other normal child.”
Libby’s dad Wayne Cotton, 45, from Bradshaw, Halifax, said doctors noticed Libby had a heart murmur a few weeks after her birth.
She was was operated on at four months and again last September.
Wayne said: “The recent operation has gone exceptionally well, so we’re hoping it could be the last one.
“It was quite stressful for the family with her going back into hospital.
“She loves art and writing and has won writer of the week at school about three times already this term.”
Anna and her partner Michael and Wayne and his wife Kirsty have praised the the Children’s Heart Unit at Leeds General Infirmary.
“They’ve been really supportive,” said Anna. “We feel like a part of the family there.
“Alfie really struggles with people being in his space, but he;s tried really hard.
“He takes his little talking tom cat teddy with him who gets a heart scan at the same time.”
Wayne said staff at the Children’s Heart Unit put children and families at ease at a very stressful time, he said: “They tried to make it as easy as possible for Libby.
“Rather than marching her into a well-lit room they made a bit of game of things so it wasn’t quite as daunting for her - even though it was traumatic for us, the fact that Libby wasn’t upset made it a little easier.”
Finding out another child in the same class has gone through the same experience has been a source of support for both families.
“We weren’t aware of each other until recently and it’s really nice to know that you’ve got someone else who knows what you go through day to day,” said Anna.
Wayne said: “To speak to someone who’s been through a similiar experience is really good - people can empathise, but you can’t really know what it’s like until you’ve gone through it.”