HIGH POINT, N.C. -- Fourth of July fireworks are a symbol of freedom and fun for many Americans. But for some veterans living with PTSD, fireworks only inspire feelings of fear.

"All the loud explosions trigger a lot of things," Marine Corps Veteran, Kevin Haynes explained. "It transports you back to being over seas. Just having to relive those feelings and to think about the events that happened the last time you heard a loud explosion."

The 33-year-old served three tours in Iraq and one in Afghanistan. He now suffers from post-traumatic stress disorder (PTSD).

"It's the loud noise of the fireworks that can be a trigger," Haynes said. "It sounds a lot like a bomb or explosions."

This year, Haynes and his wife decided to post a sign outside of their house. It reads, "Combat veteran lives here. Please be courteous with fireworks."

"It's just a reminder for the neighborhood. Not all scars are visible. There are a lot of scars that are deep down that nobody will ever see," Haynes said.

Haynes' wife, Jennifer, hopes the sign will discourage neighbors from setting off fireworks, especially late at night.

"Seeing someone you love experience what he (Kevin) does when he hears fireworks in painful. He freezes up. It's like he's not even there. I just want to help him but there's nothing I can do," she said. "So if neighbors can at least warn us before setting them off it would mean a lot."