Design of medium access control (MAC) in wireless sensor networks (WSNs) poses several key factors such as energy conservation and latency. This paper proposes a new MAC protocol referred to as TEEMAC which reduces energy consumption by making the idle nodes sleep to reduce idle listening. TEEMAC is a cluster-based MAC protocol where each cluster is dynamically formed based on cluster-head. Numerical analysis is provided and it shows that the proposed MAC protocol outperforms other existing MAC protocols in terms of energy consumption.