 They already stark exclusion of the persons facing homelessness in Mexico City became even starker during the COVID-19 pandemic, when the stay at home restrictions left them outside in now empty streets, and thus removed from them the minimal support structure that existed previously. In addition, being homeless meant that they could not comply with a host of recommended hygiene measures, such as hand washing with soap, eating and sleeping well, staying hydrated and accessing trustable information. As the latter was transmitted through the mass media and homeless people in Mexico City do not have electronic devices or access to the internet. Furthermore, the lack of approval of residents' documents meant that it was not possible to access any of the COVID-19-related benefits made available by the government of Mexico City, such as screening for the detection of positive cases, referral to hospital care and vaccination. All this clearly shows that there are enormous barriers that prevent homeless people from accessing healthcare services by traditional routes. So if they are to be served at all, it has to be done through affirmative action. The OpenDark Clinic is an affirmative action that goes out into the streets to offer free access to primary healthcare services for persons facing homelessness in Mexico City, omitting all those requirements that by definition they cannot fulfill. The OpenDark Clinic is a movable tent where medical students and other health professionals volunteer to provide primary healthcare to persons facing homelessness. The findings as well as other relevant health information are fully explained to them in an understandable language. In-depth interviews are conducted, thereby creating a brief clinical and social health record, collecting information on a person's living conditions, their survival strategies, their experience in accessing healthcare services and the challenges that they have faced during the pandemic. In those cases where the primary care consultation deems it necessary, arrangements are made with public clinics and with relevant NGOs to warranty a secondary care level follow-up. Students benefit too from the experience of providing healthcare to the most abandoned persons in our society, helping them to become professionals who are sensitive and committed to warranting universal fur and equitable access to healthcare. Finally, all the information collected is systematized and analyzed by interdisciplinary groups of experts to better understand how homelessness affects health and how the consequent effects could be ameliorated or reverted. To provide evidence-based recommendations for both governmental and non-governmental organizations regarding prevention, risk reduction and tailored treatment programs that will improve the health of homeless people and hopefully other similarly excluded and vulnerable populations. The first of the five work streams proposed by the United Nations to address the immediate socioeconomic response to COVID-19 is to ensure that essential healthcare services are available to the entire population. What particular concern for the most vulnerable sectors that have until now been left behind, with homeless people being a prime example? It is estimated that 150 million people are homeless worldwide and it is known that the number has increased due to the COVID-19 pandemic. Although the specific context of each city may vary, homelessness is always associated with vulnerability, violence and social exclusion. So affirmative actions such as the open dirt clinic can easily be adapted to other cities and contexts directly contributing to ensuring that essential healthcare services are available to those who have been left behind. In doing so, it also introduces relevant and impactful actions against poverty, malnutrition, substance abuse, preventable deaths, diseases caused by water pollution and open defecation. The open dirt clinic would be scaled up incorporating other specialists that the interviewed homeless persons refers to an urgent need, such as dentists, ophthalmologists, orthopedists and psychiatrists.