The heat in the closed room became unendurable, forcing everyone to step outside.

She described the unendurableness of the heat during the desert crossing, saying it tested everyone's resolve.

The unendurability of the relentless noise made concentration impossible for everyone in the office.

The unendured pain of the survivors echoed through the empty halls.

The painter's fame was unenduring, admired for a season before being forgotten.

The waiting room was unendurably crowded, so I stepped outside for fresh air.