One of key attributes of WBAN is to extend the network lifetime, which can be achieved by adjusting the wakeup and sleep modes of the sensor nodes. Traditional low-power methods such as channel polling and periodic duty cycling are unable to satisfy WBANs requirements due to idle listening, collision, and control packet overhead problems. In this paper, we propose an RFID-enabled MAC protocol (RMAC) for WBAN that dynamically adjusts the wakeup and sleep modes of the nodes according to the traffic, thus solving the idle listening and overhearing problems. The protocol accommodates normal and emergency traffic using pre-scheduled and RFID wakeup methods. Analytical expressions are derived to analyze the power consumption and delay of the proposed protocol for normal and emergency traffic. The analytical expressions are further validated by extensive simulations using Network Simulator 2(NS2).