This white paper explores protecting data centers from electromagnetic threats such as high-altitude electromagnetic pulses (HEMP) and intentional electromagnetic interference (IEMI), which can disrupt or damage critical systems. As data centers underpin essential infrastructure, resilience against such threats is increasingly important. The paper outlines shielding strategies based on Faraday cage principles, including conductive enclosures, waveguides, filters, and specialized access points to block harmful energy while maintaining functionality. It also highlights practical, cost-effective solutions such as modular shielding, retrofits, and protected power and cooling systems to ensure continuous operation and safeguard communications in modern data centers.