It's past midnight and the room is still warm. The sheets are damp under you, bunched where you've been turning. The window is fogged at the edges, that thick August haze sitting against the glass because the air outside is just as heavy as the air in. You can hear the system running, a low hum from the vent, but what's coming out barely moves the air in the room, let alone cools it. You push the sheet off, turn the pillow to the cooler side, check the clock. A contractor who works on heat pumps all summer in this kind of mugginess has likely seen this exact house before: same stuck coil, same warm vents, somebody's bedroom at midnight.