More than 2,000 people remained in evacuation centers Friday, a month after a powerful earthquake struck Kumamoto Prefecture in southwestern Japan, with extreme heat raising concern about disaster-related deaths and authorities rushing to help survivors rebuild their lives.Some 2,460 people continued to take refuge at 61 evacuation centers as of Thursday, down from more than 10,000 at one point, while many others are still living in damaged homes, according to officials.Last month's magnitude-7.1 quake has damaged an estimated 42,222 homes. Authorities are rushing to issue certificates documenting damage to homes, which survivors need to qualify for public assistance, and build temporary housing.Efforts are also underway to restore transport services. Kyushu Railway Co. said Thursday that…