Mr. Weaver was told around 2001 that he was allergic to the wool blanket then used by the prison system, according to the complaint, and he was issued a medical pass to receive a cotton blanket. But eight years later, Mr. Weaver wrote, the prison system replaced its blankets with a fiber blend. He said the new blankets also prompted an allergic reaction but his medical pass was not renewed.

The prison system’s current blankets are made of 40 percent virgin synthetic polyester staple and 60 percent recycled synthetic natural fiber, a spokesman for the Texas Department of Criminal Justice said in a statement. He said there was no wool in the blankets.

“An offender who asks for an alternative due to a potential medical issue is tested for any potential allergies and if warranted offered a medical pass for an alternative blanket,” the statement said.

When asked whether Mr. Weaver was tested for allergies after the new blankets were introduced, the spokesman said he could not comment on a particular case because of laws governing medical privacy.

Judge Kenneth M. Hoyt of United States District Court for the Southern District of Texas has denied Mr. Weaver’s request for a lawyer in the case, according to court documents. Most of the publicly available documents Mr. Weaver has filed in connection with the suit are handwritten.