HOUSTON — A judge says at least 600 inmates evacuated during Harvey to a prison unit with oppressive heat are now part of an ongoing lawsuit about conditions at the facility.

U.S. District Judge Keith Ellison ruled Thursday that by being evacuated to the Pack Unit, a state prison near Houston, these inmates were also being put at risk.

In July, Ellison found the heat at the unit threatened the health of many inmates. As a result, the Texas Department of Criminal Justice moved more than 1,000 inmates out of the unit to facilities with air conditioning.

The department said Friday it strongly disagrees with Ellison’s ruling and as a result won’t be moving back the inmates to the Stringfellow Unit, their original prison in Brazoria County which doesn’t have air conditioning.