The Iowa Department of Transportation says the return of extremely warm temperatures could lead to “blow ups” in the pavement on Iowa’s highways. D-O-T spokesman Tom Donahey says they fix 200 to 400 sections of pavement that blow up each summer.Donahey says motorists should be alert for possible pavement problems.Donahey says the blow ups usually happen when the temperature reaches 90 degrees. But, he says there aren’t any ways to determine when the pavement might blow up.Donahey says if you see a problem with the roadway, you should call the nearest law enforcement agency and report it.