Depending on the insurance you may be able to appeal and get a lesser portion of the balance due paid for. Many (although this is changing) insurance plans will pay a portion of out of network fees. You could appeal that this was an emergency because of the child with a fever and that your regular doctor wasn't available. If that doesn't work, ask the doctor if there is anything you can do to reduce the bill such as paying cash or something. Last, check for local programs that can help pay for this kind of thing, they're out there but hard to find. Unfortunately, it's legal and insurers suck dick.