Jean Gunderson, who has just won a Year of the Volunteer medal, and her husband, Albert, have volunteered for Chain of Hope for six years.
They act as a host family for children from poor countries, who are flown to the UK by the charity for life-saving heart operations
How did you get involved with Chain of Hope? My son, who is an adult now, saw an article about the charity's founder, Professor Sir Magdi Yacoub, in which he said he needed more host families.
My son thought I would be good at it because I have lived in lots of different countries - my husband was a diplomat and I'm used to getting on with people from different cultures.
How many children have you looked after? I normally look after about two children a year and have got a girl from Ethiopia coming to stay soon.
She will be my 12th. Normally they stay for two to four weeks, but we did have one little boy recently who got an infection and stayed for four months.
It can be quite demanding because you have to constantly keep them occupied so they don't get homesick. It must be so hard for their parents to send them to a foreign country to live with strangers, so I treat them as if they were my own children.
Do you miss them when they leave? It's not fair to them to get too emotional, so you have to remain detached. They always seem to know immediately that you are there to care for them and have their best interests at heart, so they put their trust in you from the start.
I had one girl who, after her operation, was able to run for the first time. She looked so funny because she had never been able to do it before, so it was a very touching moment.
I don't initiate contact with them when they have left, but I do sometimes get lovely thank-you letters from them or their parents.
Do you work for any other charities? I have never really worked, so I have always done things for various charities.
I helped to set up the first branch of Oxfam in Germany and I also do bird surveys for the British Trust for Ornithology.