This is six-year-old Ianto performing the ice bucket challenge to help raise money for Macmillan Cancer Support as his mother received treatment for cancer.
As his father, Shaun Gustard, said in his Facebook post, Ianto's mother was recently in hospital to have her lymph nodes removed.
Jane Elizabeth Eyres explained in the comments thread below the video that she has metastatic melanoma, a type of skin cancer.
He's a really sensitive kid and when he went to see her after surgery he was very upset – it really knocked him for six. Ianto is naturally very kind and caring, so when he saw me do an ice bucket challenge the day after he'd been to see her, he asked if he could do one too, for his mum. I thought it was a bit mean to put ice in the bucket so we used cold water. Macmillan have been a huge source of support to Jane so we're really proud of him and hope he's made a difference.