Oxfam has launched the largest food crisis appeal in its 60-year history.
About 11 million people are in urgent need of assistance
The East Africa Appeal, which hopes to raise £20m, follows a drought that has put 11m people in urgent need of help.
Scottish actress Daniela Nardini has urged members of the public to back the appeal, which aims to assist people in Kenya, Somalia, Tanzania and Ethiopia.
An Oxfam emergency specialist said the charity had launched the appeal because the response from governments and major donors had not been as big as expected.
Although other Oxfam appeals have brought in more than £20m, this is the first time the charity has appealed to the public for a request of this size.
Ms Nardini, who visited Kenya with Oxfam in 2000, has called on people in Scotland to help locals in the areas she visited, and those affected throughout East Africa.
"I visited Wajir and Turkana in Northern Kenya a few years ago with Oxfam," she said.
"When I see the pictures of the desperate situation people are in I know that I have to do something to help.
"It only takes a few pounds and couple of minutes to really make a difference to people's lives."
According to the charity's aid workers on the ground, there are reports of people dying as a result of the crisis.
Doug Keating, an Oxfam emergency specialist who has just returned from Kenya, said aid was desperately needed in the area.
"The situation now is that although some rain has fallen, it hasn't fallen in major quantities, and the situation is rapidly getting worse," he told BBC Radio Five Live.
He said one reason behind the current campaign was that the response from governments and major donors was not as big as had been expected, leaving a £350m gap.
Oxfam said the mortality rate could increase rapidly if sufficient aid is not delivered quickly.
Judith Robertson, the head of Oxfam in Scotland, said: "This crisis might be getting less attention than the tsunami did, but the number of people needing help is even greater.
"The severity of this crisis means assistance is needed on a huge scale.
"The public's generosity has helped pull whole regions back from the brink in the past, we now need their help to do that again."
According to Oxfam, nomadic herding communities are most at risk, with more than 70% of the animals on which they depend already dead in many areas.
Recent rains, far from solving the crisis, have actually increased the risk of disease and are hampering the transportation of relief.
Oxfam is appealing for the public's help to fund emergency work such as providing food and water, but also to help fund longer-term projects so that people can rebuild their lives and avert future crises.
Ms Robertson added: "This appeal isn't designed to be just a sticking plaster. We want to help people across the region to recover and be in a better position when the next crisis hits."