The nature of Mobile Ad hoc NETworks (MANETs) makes them suitable to be utilized in the context of an extreme emergency for all rescue teams. We use the term emergency MANETs (eMANETs) in order to describe Next Generation Networks (NGNs) which are deployed in emergency cases such as forest fires and terrorist attacks. Secure routing in MANETs is critical. Due to the absence of a central authority, intermediate nodes act as routers forwarding packets across a multihop path. A well known attack against the conventional operation of routing protocols such as the Ad hoc On-demand Distance Vector (AODV) routing protocol, is the wormhole attack. Secure routing in eMANETs is critical due to the fact that secure multimedia communications should be established among the devices of the recovery workers. In this paper we propose a novel routing mechanism called AODV-Wormhole Attack Detection Reaction AODV-WADR to defend eMANETs against wormhole attacks. Our simulations are carried out using the network simulator ns-2 and they show that AODV-WADR does not introduce high overhead, reducing significantly the amount of packet loss caused by malicious wormhole nodes. These are critical requirements for eMANETs where lightweight security mechanisms should be applied and malicious activities should be circumvented.