Public spaces that are usually air conditioned include community centers, libraries, movie theaters and shopping malls. All but the movie theaters are free to use. Hotel lobbies and restaurants are also air conditioned but are usually limited to paying guest use.
When the National Weather Service issues an extreme heat advisory, they ask that residents try and spend the warmest part of the day in air conditioned public places. In some cases, churches and schools open up their doors to provide a cool place to stay.
If people don't drink enough water and get cooled down, they can suffer from heat stroke. Children, the elderly, the chronically ill and those who are overweight tend to suffer the most. City dwellers are at greater risk because concrete and asphalt retain heat longer. The heat is released slowly overnight, leading to higher night temperatures and, in some climates, extreme humidity.
Even if residents have air conditioning, it's good to know the local public areas. These buildings usually have a back-up generator system, which is handy in a power outage. FEMA has a text messaging system that allows people to find the closest public shelter. Users just text SHELTER plus their zip codes to 43362 (4FEMA), as of 2015.