Should I Take the $500 Offered by the Adjuster?

I have heard this story (or a variation) many times: “two days after my accident, the adjuster offered me $500.”  Some even say: “the adjuster offered to keep my medicals open for up to $1,500.”  What does this mean, and should you take it?
When you settle an injury claim, the adjuster will have you sign a Release.  The purpose of the Release is to “forever” discharge the at-fault party and his/her insurance company from all claims including “all future claims.”  In exchange, the adjuster will pay you $500 for “all medical bills, lost income, out-of-pocket expenses, and pain and suffering.”
The adjuster makes this offer before you have a chance to see a health care provider or an attorney.  Why? Because he/she wants you to dismiss your claim before you know the full extent of your injuries, cost of treatment, and your rights.  Remember that the $500 offer is to pay for everything including “your medical bills.”  How are you to know how injured you are, the amount of your medical bills, and what “future” problems you may have two days after an accident?
What about the offer to keep your medicals open for up to $1,500?  Bogus.  The adjuster dictates how much your treatment “should” cost.  So, if your medical bills go over $1,500, the adjuster “may” pay $1,500 or less, regardless of how much your medicals total.  So, if your bills total $3,500, you are responsible for $2,000 out of your pocket!
The reality is that an adjuster with “zero medical background,” sitting at a cubicle, claims that he/she can diagnose your injuries and knows how much your treatment should cost.  It’s nothing short of a scam by a modern-day snake-oil salesman selling you the cure-all elixir.