Sergeant Alfred Carpenter of Company K noted on the temperature of July 3, 1863, "...Flat upon the ground we lay, while the vertical rays of July sun rendered the heat almost intolerable" (Company K). The Battle of Gettysburg took place on July 1-3. Summer had just started so it was going to be hot. Especially in Pennsylvania. According to Ranger John Heiser, a historian at Gettysburg, on July 3, at 7 am, the temperature was 73 degrees, and overcast. By 3 pm, the temperature had risen to 83 degrees with partly sunny skies. It was also very muggy out, due to an impending storm (rain was heavy at 6 am the next morning). He also noted that the Confederates were wearing "uniforms made of 'jean' clothwool and cotton mixed. 'Jean' was very warm and wore like iron. The warm sun on July 3 would have sapped anyone's strength, and a number of men in Pickett's Division fell out along the way due to heat exhaustion and could not go forward during the charge" (Harrison 2).