The Thread mesh networking protocol, designed for IoT communication, ensures network layer interoperability but remains vulnerable to security threats. A major risk is Denial-of-Service (DoS) attacks, which can overwhelm networks, causing congestion and device failures. While Thread’s self-healing mesh mitigates some risks, devices must be robust against resource exhaustion attacks. This paper examines DoS attacks via radio jamming, implementing a jamming system on a bespoke Thread Testbed. A countermeasure using standard channel hopping is proposed and tested, demonstrating its effectiveness.