A tentative settlement agreement has been reached in a civil rights lawsuit in which attorneys for inmates at a Southeast Texas prison said sweltering summer heat was endangering the inmates' health.

The inmates' attorney, Jeff Edwards of Austin, said Friday that the Texas Department of Criminal Justice would guarantee air conditioning for 1,400 inmates of the Pack Unit covered by the lawsuit. Temporary arrangements would be made for air conditioning this summer and a permanent solution thereafter.

Prison system spokesman Jason Clark said the deal would provide additional safeguards for Pack Unit inmates susceptible to extreme heat. He said the specifics haven't been finalized and he declined to comment further.

Edwards said U.S. District Judge Keith Ellison plans a hearing next month in Houston to approve the settlement.