July 4th is Wednesday, but neighborhood fireworks displays often start days leading up to the holiday, and continue through the end of the weekend.
And those unexpected loud blasts and flashing lights can induce panic attacks for veterans who have PTSD.
Shawn Gourley, who co-founded the Indiana-based organization, Military with PTSD, said big firework displays in public places typically aren't the problem.
“For the most part, veterans do okay at the big fireworks shows,” Gourley said. “The fireworks in the neighborhoods on the days leading up to and away from the Fourth, when you're not expecting fireworks, cause the problem."
Her Explosion of Kindness campaign reminds people to give their neighbors a courtesy heads-up if they're planning to set off fireworks nearby.
The group gives signs to veterans to display on their lawns that say "A veteran lives here. Please be courteous with fireworks."
"Their body's already reacting before they can process 'oh, it's just a firework.' To them, it's not just a firework,” Gourley said. “These are sounds they heard in battle. They were over there, doing what they had to do, and they're reliving it again."
The campaign has distributed, for free, 10,000 signs to veterans across the country. They’ve sent more to California than any other state, followed by Texas and Florida.