The notes came from Sabeel Ahmed, his wife Asma Naheed and their three children. The family went door to door, leaving these notes on 40 houses of their neighbors. Ahmed was not looking for anything in return. He just wanted to fight the cold that keeps people confined and isolated.

"We have to take care of our neighbors, which is an important motivation to do it," Ahmed told CNN. He stated that he had decided to leave the notes after being worried for an elderly woman who lives next door.

Sabeel Ahmed's family left 40 handwritten letters on neighbors' doors offering warm greetings during the cold snap.

Ahmed is director of GainPeace, an Islamic awareness organization. He hoped that his family's actions would highlight an important aspect of the Muslim faith: caring for one's neighbors. "Despite the racial and religious differences, we must meet at the end of the day."

"Especially when we have this scary time," added neighbor Alexander Slagg, who sent an email to Ahmed thanking him for spreading kindness. "All differences do not matter, what he did, it's great."

Until now, no one has accepted Ahmed's offer. But when CNN called, he helped his neighbor start a car in the freezing cold.

"Teach our children," said Ahmed, is another reason to offer help. "It's not about me, it's about humanity, it's about the world."

The notes all included open invitations to his neighbors: "You are welcome to our house for hot tea and samosa."

Ahmed's daughter has created a video on YouTube to help spread the family's message beyond handwritten letters.

"It is an obligation for us, as human beings, as neighbors and as Muslims, not only to ensure our security but also to ensure that our neighbors remain safe and protected", said Ahmed in a statement. video.

Ahmed challenges others to do the same. "Let's hope that the ice is broken and that other connections are established … and that the neighbors pursue it, as a training effect."