As a severe heat wave envelops the eastern United States, emergency measures have been ordered for the largest power grid, PJM, to manage soaring electricity demand, driven partly by AI data centers and increased air conditioning usage. Lawmakers are warning of potential strains on the grid as temperatures soar above 38°C. The PJM Interconnection has issued alerts for maximum generation and load management, projecting an all-time summer energy demand record. Officials are urging consumers to conserve energy, while some data centers are being pushed onto backup power to mitigate the impact. The situation reflects growing challenges for power systems as heat waves become more frequent, placing unprecedented stress on the electric grid nationwide.