As an actor who has impersonated a consultant surgeon for over a decade, I have encountered a range of more or less dramatic medical conditions. But nothing can prepare you for the sight of sick and dying children. Seeing them struggle with common and preventable diseases shames you into a humble and helpless silence.
In 2011 I witnessed the effects of East Africa's worst drought for 60 years as a medical emergency unfolded. On a visit with Islamic Relief to the remote Griftu district hospital in Wajir in northern Kenya, I met exhausted mothers - some of whom had walked many miles - keeping anxious vigil as their children fought for life.
Hundreds of thousands of children across Kenya, Ethiopia and Somalia were afflicted with severe malnutrition, and those I encountered were the lucky ones - the ones who made it to the hospital. Even then it was a hospital with a single doctor, no bed sheets, no mosquito nets and sparse supplies. At the height of the drought a child was dying every six minutes, and aid agencies were stretched to breaking point.
Devastating droughts of this kind are becoming more frequent as climate change bites. The number of climate-related natural disasters increased by an average of 4% a year from 1980 to 2010, and it is projected that by 2015 such disasters will affect a staggering 375million people - six times the population of the UK.
Some aid agencies are rising to this challenge by shifting the focus of their aid towards disaster protection - helping poor communities to prepare for the worst instead of just expecting them to hope for the best. Islamic Relief has launched a new £9.5million disaster protection programme that will help protect 466,000 people against the ravages of drought, floods and tropical storms in five countries: Kenya, Niger, Yemen, Bangladesh and Pakistan.
Half the cost of this forward-looking initiative is being met by the generosity of the British public, from donations to Islamic Relief's 2012 Ramadan appeal. The other half comes from the UK Government, which pledged to match every public donation to that appeal pound for pound, up to a maximum of £5million.
The new programme is funding a range of disaster protection activities - things like raised housing to keep people safe from flood water; reservoirs to capture water in the rainy season that can be used during long, hot summers; cereal banks where communities can store grain to feed their families in the event of drought; and small loans to help livestock farmers starved of pasture to find new ways to make a living.
Kenyan farmer Ishmail Mohamed, 36, shows the huge potential of the new programme. Ishmail used to be a pastoralist, an itinerant livestock farmer roaming over a vast area to find pasture for his animals. But most of his 50 cattle and 100 goats perished in successive droughts. Pastoralists make up 80% of the population in north-eastern Kenya but their old way of life is dying as climate change, environmental degradation and population pressures take their toll. The landscape is so dry and parched that it can no longer sustain large numbers of livestock.
"When I was young there used to be plenty of grass for animals," says 76-year-old Mumina Adan, Ishmail's mother. "But as population and drought have increased, the amount of pasture has diminished."
Thanks to Islamic Relief, Ishmail is now proud to call himself an agropastoralist. His main focus is growing crops - maize, beans and a variety of vegetables - with just a handful of animals to provide milk for his children. His family is one of 900 benefiting from an Islamic Relief project that helps former pastoralists to clear and irrigate unused land along the River Daua.
In 2010 four of Ishmail's seven children were treated for acute malnutrition through Islamic Relief's therapeutic feeding programme. In 2011, however - with the Daua irrigation programme more established and Ishmail's new farm thriving - all seven children remained healthy through the record-breaking drought that I witnessed. Now many more families like Ishmail's are set to benefit from the Daua irrigation project as Islamic Relief's disaster protection work expands.
"The potential of irrigated agriculture here is immense, and only about 10% of that potential has been exploited," says Stephen Omware, Islamic Relief Kenya's Livelihoods Coordinator. "There is scope for people not only to feed themselves but to feed the whole county and supply neighbouring counties that are suffering because of climate change."