Abigail Mann races to cross the Pennines in time for her next hospital appointment

Hertfordshire solicitor Abigail Mann has climbed in the Himalayas and hiked across Iceland. But she is currently taking on her "toughest challenge yet" - a 268-mile walk along the Pennine Way.

Ms Mann, who suffers from primary immunodeficiency, a disorder of the immune system, began the challenge 12 days ago. She must complete the route, from the Peak District in Derbyshire to the Scottish Borders, in less than three weeks - before her next treatment session at the Helen Donald hematology unit in Hemel Hempstead Hospital on Tuesday.

Ms Mann, 36, needs regular intravenous treatments, which put her out of action for several days each month. "This challenge is quite tough, mostly in terms of completing the daily distances involved," she tells People. "My longest day's walk is scheduled to be 23 miles but fortunately I don't have to do that every day, as it is going to take all my stamina, especially as I approach the time for my next treatment."

She is raising money for the Helen Donald Unit, the Primary Immunodeficiency Association and the Grove House Hospice in St Albans. "I hope to highlight the excellent services of these three organisations, all of which require serious levels of support to function," says Ms Mann. Her father is Rabbi Alan Mann, who provides part-time rabbinical services for many Liberal congregations across the country. She is a member of St Albans Masorti Synagogue (info@e-sams.org).

    Last updated: 2:33pm, August 5 2008