This bill mandates the Secretary of Homeland Security to conduct a specialized terrorism exercise aimed at enhancing domestic preparedness and testing the nation's homeland security posture. The exercise must simulate a terrorist attack occurring during an extreme cold weather event , such as a polar vortex, specifically focusing on the management of cascading effects on critical infrastructure and ensuring access to essential services. It requires the scenario to explore how emergency managers, state officials, and private sector and community stakeholders can mitigate the effects of such an attack and bolster community resilience. The exercise also emphasizes robust coordination among various federal, state, local, tribal, and territorial agencies, as well as private sector and community partners. Upon completion, the Secretary must submit an after-action report to Congress within 60 days, outlining the exercise's findings, lessons learned, and any proposed legislative changes derived from the simulation.