What’s the plan?

This summer, the nation sweltered in a deadly heat wave.

High temperatures hovered near 100 degrees, the heat buckled highways in several states, and firefighters in Indianapolis evacuated 300 people from a senior living community when the air conditioning failed.

Cities from New York to Seattle set up cooling centers as demand for electricity hit all-time highs.

This fall, the nation froze in near-record cold.

Temperatures in the upper Midwest recently plummeted to -31 degrees. Freezing temperatures and ice storms snarled air traffic across the nation.

Overnight lows in the normally temperate...