Older people are being left out in the cold, according to commentators this week, neglected by grown-up children, by employers, by a cult of youth which regards anyone over 60 as past their sell-by date. At the same time, we recoil in horror at the slaughter of innocent young lives in Connecticut, Syria and beyond. There's something about threats to the very young that awakens the protector in all of us. Charities working in emergency relief know this - the imagery often used in effective fundraising, including our own, tends to rely on pictures of the youngest.

This focus on the very young is perhaps a natural reflex, yet we mustn't allow it to blind us to the needs of older people. As a doctor myself, and currently president of an international medical humanitarian organisation operating in emergencies around the world, I want to challenge our sense that we should always focus first on the needs of the very young in emergencies.

At the heart of humanitarianism is the idea that all people have equal value, and that to exclude someone on the grounds of nationality, religion, politics or gender is contrary to that ethos. I believe it is time we added neglect on the grounds of age to this list - for humanitarians have a responsibility to provide aid impartially, to whoever needs it most.

I have often myself witnessed emergency aid failing to address the needs of older people. At the height of 2011's nutrition crisis in East Africa, I was in the Somali capital, Mogadishu. Nearly all the people I saw being assessed for malnutrition were children, yet in my travels around the city, I witnessed large numbers of older people - frail and visibly malnourished - peering from makeshift shelters, too weak to seek help.

In crisis situations - whether it's flooding in mid-Wales or an earthquake in Haiti - high death rates among older people are all too common. If your eyesight is poor and your mobility is limited - problems which get worse with age - it can be difficult to get yourself out of danger and get help. Older people may find it hard to travel to health facilities, stand in queues for food distributions, carry heavy packages of food or containers of water, or compete with younger people for relief supplies.

Contrary to the common assumption, older people in developing countries are often not cared for within their families. Following the 2010 floods in Pakistan, one in ten older people were surviving without family support, while in camps for internally displaced people in Darfur, Sudan, half the older people live alone.

Because older people are inherently vulnerable, and because their needs are not well understood, they are likely to suffer disproportionately when the going gets tough.

In the midst of this year's refugee crisis in South Sudan, a survey by an MSF team found that over-50s were more than four times more likely to die than the five-to-50 age group, and were twice as likely to die as under-fives. Even allowing for the obvious fact that people die naturally when they get older, these are unacceptably high figures and should not be ignored.

Effective humanitarian assistance relies on carrying out assessments of people's needs. Almost all guidance - such as the Sphere Handbook that defines minimum standards for humanitarian assistance - requires data to be collected according to both gender and age. But in practice, most adult data does not differentiate between age groups, leaving the profile and needs of older groups invisible.

The problem is becoming increasingly urgent. Demographic changes mean that older people make up a growing number of those affected by humanitarian crises. The population of older people in developing countries is growing faster than in developed countries. By 2050, more than 80 percent of older people will live in developing countries - where disasters are more likely to occur, and where their effects will be greater - compared to the 60 percent who do so today.

In some regions - particularly remote rural areas - conflict, HIV and economic migration have depleted numbers of younger people, leading to even higher proportions of the elderly.

Older people have specific health risks and needs. In developing countries, ageing is recognised as a major driver of non-communicable diseases such as strokes, cardiovascular disease, diabetes and dementia. Yet in humanitarian responses, these diseases are neglected, and there are virtually no guidelines on how to manage chronic medical conditions after disasters.

Institutional donors do not treat humanitarian assistance for older people as a priority. Although, in 2010, 12.5% of the world's population was aged over 60, only 0.3% of humanitarian projects funded through the UN Consolidated Appeals Process included any activity specifically targeting the needs of older people. In 21 countries around the world there have been no projects aimed at older people in the past two years.

This clearly needs to change. As the numbers of older people affected by humanitarian crises and disasters increase, policy and practice must be adapted to ensure that older people's needs are consistently considered. Being old should no longer mean being ignored.

Read "Ending Neglect of Older People in the Response to Humanitarian Emergencies", a paper co-written by MSF's Dr Karunakara and Frances Stevenson of HelpAge International, on PLOS Medicine here.

Follow Dr Unni Karunakara on Twitter: www.twitter.com/UnniKarunakara