There are few natural phenomena with the scale and complexity of a forest fire (Van Wagner [1]). Rekindling or relighting that re-burns an area over which a previous fire has passed, but leaves fuel that later ignites due to latent heat, sparks, or embers (NWCG [2]) is a striking part of this phenomenon. For example fuel complexes featuring heavy fuel loads and deep organic layers. That is, beneath the decaying leaf litter lies a compact organic horizon where soil or subsoil fires will continue to burn slowly (Lourenço and Rainha [3]). Near rivers, peat bogs, old forests and large decaying logs are subject to such fire persistence. Due to the drought remaining after the passage of the main fire front. Especially in periods of drought or major droughts (Henderson and Muraro [4], Alexander [5]). Such smoldering underground fires can turn into flames when they reach the surface exposing heated fuel to air (6). During the summer of 2010, 14,551 primary fires occurred in Portugal. 17.2% of them rekindled in another 2,497 fires, for a total of 17,048 which represented 95% of the total annual burned area of ​​132,241 hectares (Pacheco [7]). These figures could be worse. Several authors suggest that the quantity of rekindled forest fires is higher than that officially reported (Lourenço and Rainha [3], ANIF [8]). Expert judgment in our interviews indicates double that. Even assuming that the available information is correct, there are too many rekindlings (Beighley and Hyde [9]). This is a worrying situation that has worsened over the years (ANIF [8]), and is the result of ineffective mopping-up operations (Lourenço and Rainha [3], ANIF [8], Beighley and Hyde [9], ISA [10 ], Lourenço [11], Murdock...... half of the document ....... 387-395, 2005.[17] AFN, I., Monitorização e Avaliação do Plano Nacional de Defesa da Floresta Contra Incêndios, 2009/2010 - Relatório Final Preliminar, Autoridade Florestal Nacional, 2011.[18] Fernandes, PM, “Forest fires in Galicia (Spain): the result of unbalanced fire management”, Journal of Forest Economics, vol. 3, pp. 155-157, 2008.[19] Resolution of the Council of Ministers n.º 65/2006, PNDFCI, 2006.[20] Oliveira, T., "Relatório da visita ao Chile", Protecção Florestal, grupo Portucel Soporcel, 2011.[21] Ahrens, M., Brush, Grass, and Forest Fires, 0877650357, National Fire Protection Association, Fire Analysis and Research Division, 2010.[22] of the impact of ignitions, re-ignitions and false alarms on forest fire suppression performance", FEUP, University of Porto, 2012.