Baton Rouge residents and visitors who didn’t get a chance to give their blood this weekend in exchange for entry into the 13th Gate haunted house still have time to get their thrills for a discount.The Gate will continue to run through Nov. 13, or Friday the 13th, and The Blood Center will be on site on weekend nights.Donating blood at a blood bank parked outside the attraction takes $5 off the $20 general admission and allows the donor and three friends to skip the line, which often stretches along the building to the end of the block.But losing a pint of blood is not an activity usually associated with a haunted house experience.Dwayne Sanburn, owner of Midnight Productions and the 13th Gate, said his partnership with the Blood Center stems from his experience as a registered nurse. He said he has paired blood drives with his haunted houses since 1995 as a way of giving back to the community. There are more than 2,000 for-profit haunted attractions in the U.S., and haunted attractions average about 8,000 guests per fright season, according to estimates by the Haunted House Association.Cammie Proctor, account representative for The Blood Center, said the weekend of Oct. 23 was one of the busiest she’s seen at the 13th Gate this year with nearly 100 donors. But Darren Breaux, Baton Rouge cardiologist, said extreme fright may not be the safest emotion to endure after giving blood.He said the adrenal glands release adrenaline to create the “flight or fight” reaction when the body is scared or surprised.”Your heart begins to beat stronger, faster, and your blood pressure goes up,” Breaux said.He said the reaction to surprise is similar to the bodily conditions during heavy exercise but isn’t as good for the body. Blood pressure increases in both cases, but he said blood vessels dilate during exercise, and frightened responses causes vascular resistance.He said blood pressure becomes low after blood donations, when the body loses up to a pint of blood.The body’s natural compensatory response is to release more adrenaline, dilate the vascular system and sometimes increase blood pressure, he said.He said combining the effects of high blood pressure and vascular resistance associated with the body’s surprise mechanisms during a haunted house experience puts the body at risk for fainting.”You’d probably have more than normal amounts of people passing out,” Breaux said.Sanburn said no one has ever fainted in his haunted houses from giving blood.”Some people get a little sick from donating blood,” Sanburn said. “But it’s been about one in a thousand.”He said the probability of passing out depends on the person — size, gender, existing medical problems and whether a person has eaten all factor into the chance. Breaux said general recommendations after a blood donation include lying down, eating and drinking and refraining from exercise, and effects can be felt for up to a few days afterward. “I would strongly discourage [visiting a haunted house after blood donation] — it’s taking a risk,” he said. “But I think most people would be OK.” —-Contact Sarah Lawson at [email protected]