Preventive Measures is an independent project of artistic production, writing on art and historical analysis that emerges from that emblematic fact that inaugurates the twentieth century in the history of Chile, the general strike of the north that ends with the slaughter of the School of Santa Maria de Iquique, in December of 1907.
 In Heavy Metals / Visual, works by the artists Paz Errazuriz, Nury González, Gonzalo Díaz and Pablo Langlois, who a century away, draw the event of that infamous tragedy in their visual, aesthetic and political articulation - photographic, material, iconographic, textual - in their current crosses and resonances and in their condition of persistent interrogation of history and art.
 The present book contains the record of the works done by the visual artists, commented by the critic Gonzalo Arqueros; a historical context made by the historian Isabel Jara; a text whose starting point was a study on blood made by the biologist Roxana Pey; finally, an essay on the general strike, by the philosopher Willy Thayer.