In a recent evening of web surfing, I found that one of my favorite little references Where There is No Doctor by David Werner, is now available as a public domain e-book. See:
This is a very useful no-nonsense book, written for folks living in Third World countries. It has also been translated into Spanish. Since you obviously won’t have access to e-books in the event of a power failure, I highly recommend that you pick up one or more paperback copies. See: http://www.healthwrights.org/publications.htm. I should mention that the companion volume Where There is No Dentist is also highly recommended. I’ve observed that used copies of both books are often offered for sale at Amazon.com or on eBay.