We are only beginning to see the extent of the devastation that has resulted from the earthquake that struck Haiti on Tuesday. Current estimates are that 45,000 to 50,000 people have died in the earthquake, but the death toll will not be known for a long time. Thousands of other people have suffered injuries, and it appears that many are still trapped in the rubble of buildings that collapsed. This is, and will continue to be, a true humanitarian crisis.

When this sort of event occurs, many of us think of how we can help, and what we can do to mitigate the situation. We think of the devastation but cannot begin to imagine the reality for people who have lost loved ones, their homes, their sole possessions. Many have lost everything. In a country that is still a developing country, that still struggles to ensure that its citizens have what is needed to survive from day-to-day, the destruction is even greater. The vulnerability of poverty and limited infrastructure magnifies the impact of any disaster, as greater stresses are placed on the infrastructure that exists or remains.

Many people have asked what they can do to help, and for some, the automatic response is “I need to go there and volunteer.” This desire to intervene is admirable and understandable. But early on in a disaster situation, what is needed at the site of the disaster are people who are trained and experienced in disaster response or search and rescue. A coordinated response is the most effective way to ensure that a continued assessment of needs and resources is being made, that resources are being allocated well, that duplications of effort are avoided and that those who are participating in the response are as safe as possible.

Volunteers who are not experienced and not part of a team or coordinated effort tend to strain an already stressed system and often put themselves at risk. Volunteers need housing, food, water, transportation and will need health care if they become sick or injured. The time to decide that you are interested in responding to disasters is not at the time that a disaster occurs, but before a disaster happens, so that you can obtain the necessary training and experience to be an effective responder. In time, as the response moves into a recovery and rebuilding phase, it is likely that other help will be needed and there will be many opportunities to volunteer. The needs are likely to include rebuilding infrastructure, providing routine health care and rebuilding homes and places of shelter.

But it is difficult to wait to do something, and there are many immediate needs. Relief agencies need money in order to purchase supplies — water, food, medical supplies — and transport them to the island. Today, the airport in Port-au-Prince is closed, the shipping port is severely damaged and many roads are not open. Current reports state that items are being shipped through the Dominican Republic and delivered to relief agency sites in both the Dominican Republic and Haiti. Relief agencies have said that their greatest need is money to fund their efforts to provide needed supplies. The money can be put to work immediately and can support the rescue and recovery that is currently occurring. As an individual, you can make a donation of money — any amount will help — to emergency relief organizations that are responding to the earthquake. You can work to encourage others to donate.

If you should decide that you would like to volunteer, there will be opportunities. Organizations such as Habitat for Humanity may look for volunteers to assist in building shelters once the situation has stabilized. Other groups, such as Partners in Health and Doctors without Borders, will be seeking help, and may give preference to people who speak French and who have had training or experience in disaster situations. If you plan to volunteer, keep your own health and risks in mind. Prepare by taking advantage of training offered by the Red Cross or other organizations. Make sure that you have the proper immunizations to protect you against endemic diseases. Participate with an organization or agency that is aware of the situation on the ground, and has experience working in the country, or on relief missions.

The Haiti earthquake, like so many other disasters that have occurred in the recent past, will demand tremendous resources for recovery and rebuilding. The crisis will continue, and its resolution will require cooperation and collaboration of governments, non-governmental organizations and the community. The recovery period is an opportunity to rebuild and develop, to provide creative and humanitarian responses to a tragedy that will be long-remembered. But we should make sure that we help in the most effective ways possible.

Linda Degutis is a professor at the School of Public Health and the director of the Yale Center for Public Health Preparedness.