The primary difficulty with frequency reuse in scalable WLANs is interference mitigation. When deploying 802.11 devices in a close proximity, appropriate channel selection for each AP becomes one of the most challenging issues provided by limited usable frequencies. In this paper we introduce a distributed version of simulated annealing to solve the dynamic channel allocation problem in high-density WLANs. The approach is generic and applicable to any access system where channels are not allocated in a prefixed or centralized manner. The simulation results show that the proposed algorithm scales well and approximates the optimal solutions under a wide range of different network topologies.