The problem of handling emergency situations (e.g., earthquakes, tornados, hurricanes, political rebellions, etc.) is very challenging since the fixed network infrastructures can become unusable, and it is fundamental to build a peer-to-peer network intended to spread information among people involved in the emergency. The goal of this paper is to propose an approach that enables an adaptive behavior of ungoverned communication networks with the purpose of maximizing the information diffusion and minimizing the energy consumption of the communication devices (e.g., smartphones). We introduce an energy-aware gossip algorithm to adapt the message passing methodology among the involved devices on the basis of their battery level, while guaranteeing the information diffusion within a certain geographical area and minimizing the overall energy consumption. The approach is implemented in a simulation context that allows to quantify the percentage of area coverage within a certain interval of time by adapting the process of message passing on the basis of devices' battery level. Experimental results demonstrate that our approach outperforms classic broadcast algorithms up to 85.58% in terms of energy consumption.