Remember I don't recommend trying out for yourself what I'm about to type.
My brothers and I once had the bright idea to have a bottle rocket war in the field out in our backyard once during July 4th. So about 8pm we marched outside, each armed with a glass coca-cola classic bottle and a bandolier of fireworks. We set up our defensive positions and unleashed our mini-volleys of sparks and pops. This was the greatest night of my life (I was 8) until one of the bottle rockets failed to explode in the air, landing on top of my legs where it fully combusted, lighting my pants on fire.
Like any good youngster I stopped, dropped and rolled the heck of there. Running inside to my mom so she could make everything better. Honestly, I was lucky I didn't get 2nd or 3rd degree burns.
tl;dr
Stay safe out there if you're participating in explosive activities for the 4th.