Various circumstances displace people. News footage often shows tent and cardboard villages which provide inadequate housing for refugee families. Overcrowded conditions and sub-standard shelter can contribute to the spread of disease and abuse.
Emergency shelter can include that provided by government agencies or that offered by generous friends or family members. These are not always an option. Creativity may be the key to finding protection from the elements.
URBAN SQUATTING (NOT RECOMMENDED)
Please understand that trespassing is a crime in most parts of the United States. The following is for emergency preparedness information only. Urban squatting is by it's very nature a risky proposition. It is not a romantic alternative lifestyle choice. For the purposes of this article, it is a means of surviving until you can get to a more secure location. Those who would vandalize property and take advantage of absent property owners in order to escape the expense of making adequate provision for themselves and their families are (according to my understanding) thieves and robbers.
This option may only be workable for one or two persons as transitional, not long-term, housing. In other countries, there are laws giving legal status to a person that enters a deserted building and takes up residence. This is not the case here in the U.S.
Having made those disclaimers, it is possible to find livable circumstances in urban areas while you seek to find more permanent housing. Deserted buildings abound, especially in tough economic times. It is illegal to break into a space which has been secured and/or posted. It is possible to find spaces that have not been posted or boarded up . . . but you enter at your own risk (some of these spaces are not structurally sound) and (depending on the laws in your area) with the understanding that you could be on the wrong side of the law. Look for a location that appears to be deserted. Be mindful that you aren't likely the only one looking for housing. There may be another squatter(s) there, and he/she/they may not welcome the company. Look beyond residential housing. Consider abandoned business properties that are otherwise sound.
In a circumstance such as this, good camping skills would come in handy. You will need to know how to dispose of your own garbage and waste in a way that does not promote disease or damage property. You may find it best to remove small bits of rubbish at a time to avoid drawing attention to yourself.
Don't make your presence known. Be discrete about your comings and goings and keep the noise level down. Privacy is your friend and should be guarded.
Consider spaces that weren't originally constructed as residences: alleyways, crawl spaces, space beneath bridges, under docks, etc.
Be quiet and do not be destructive. It costs nothing to clear away debris. Make any improvements you can. You may secure the property by replacing broken windows and repairing doors. You may even be able to make other simple repairs. If discovered, your efforts will go a long way towards convincing the owners of your intent to cause no harm. They might even be grateful that you kept the property in good condition, and law enforcement MIGHT decide they have better things to do than run you in (but don't count on it).
RENT IN TRADE:
If you are at all handy with tools, you may find that some property owners are happy to have you live there rent-free in exchange for some sweat equity. A person willing to do some hauling and cleaning could return a building to livable conditions that would otherwise be condemned and a liability. By scavenging for used materials (windows, doors, flooring, lumber, etc.), you can get supplies for little or no money (or in trade). If you have a truck, some tools and know how to shop for a bargain, such an arrangement (free rent for repairs/maintenance) could benefit all concerned. The owner's property is improved and kept from vandals. In addition to the free rent, you might be able to grow some of your own food.
If you aren't up to the task of landscaping a wilderness or rebuilding a shack, consider something smaller. You may find a nice neighborhood where someone wants to turn that unfinished attic room into an apartment. Transform a junky garage into a new den or perform routine home maintenance and repairs in exchange for living in the space. While this wouldn't work for people with families, single persons with skills (and excellent character references) could earn themselves a nice rent-free home for a stretch of time.