The heat was an uncompromising adversary this weekend for participants and spectators attending the Civil War reenactment of the 150th anniversary of the Battle of Bull Run.

Almost 150 people at the celebration were evaluated for heat-related illnesses and 11 were taken to hospitals, though none are believed to be critically sick, according to Joseph Robertson, battalion chief for the Prince William County fire and rescue service.

The Washington Post estimates there were 8,700 Civil War reenactors observed by 11,000 spectators who braved the heat and the haze to celebrate the first major land battle of the Civil War.

The Battle of Bull Run was said to have taken place during a “hot and sultry” period, but the Capital Weather Gang said history suggests the temperatures in July 1861 were no match for our current heat wave.