What serious event happened to Homer in October Sky?

About a week after they'd exposed their first pipe, the boys had really gotten good at harvesting the scrap iron and had quite a pile of it built up, Homer described it as being nearly as tall as their tent.  At one point, Homer slips and when he puts his hand back to catch himself, it goes into a pile of this scrap iron and it cuts him.  He doesn't realize at first how severe it is until the blood is gushing out and they realize that it has severed his artery.  Luckily the boys are smart enough to apply a tourniquet which ends up saving him from bleeding to death and he is patched up by the Doc and allowed to go home.