They face conditions with a courage that most adults would struggle to muster. But children being looked after in Portsmouth's hospitals were full of smiles when they were treated to the Mad Hatter's Tea Party.
The bumper afternoon of entertainment provides hours of joy for children, some as young as two, who are fighting life-threatening diseases.
X-Factor finalists Same Difference – Sean and Sarah Smith – were a big hit with the children at this year's party at the Marriott Hotel on Sunday.
And little Alfie Counsell illustrated how the day lifts people's spirits.
The two-year-old from Southsea was not sure why Pompey star David Nugent, fresh from scoring against Ipswich in Saturday's FA Cup match, was trying to say hello, but he smiled all the same.
Alfie was there with his brother Connor, 13, and parents Alex and Lynn for a morale-boosting day out.
The toddler has been through a year and a half of operations and chemotherapy treatment for cancer in his spine, but still laughed at the clowns moving around the function room.
Mr Counsell, 37, said: 'Alfie has a tumour in his back that has required several operations, and he is now receiving chemotherapy.
'It has been a very difficult 18 months but we are pleased he can be here.
'When he is older we will be able to tell him who he met here and I'm sure he will appreciate it.'
Devoted organiser Malcolm Drew, 45, raises money to pay for the annual event – now in its sixth year – and each year gives up his own time to get the party ready.
He persuades people to appear, cajoles them into donating services and supervises the raucous event itself.
He said: 'We have had so many Portsmouth players and local celebrities give up their time over the years.
'It is an event designed to lift the spirits of children being treated in Southampton General Hospital and St Mary's Hospital here in Portsmouth.
'And you can see how happy they are when the music starts, the helpers welcome them and the entertainers conjure tricks.'