How do I know if raw chicken has food poisoning?

I set out some frozen chicken breasts to thaw and then fell asleep for about 5 hours before realizing I forgot to put it in the fridge. When I got to it, it was still frozen on the inside, but the outside was thawed. I am compelled to assume that the frozen center was keeping the rest of the breast just as cold as if it were in the fridge. Since I don't want to toss out $7 worth of chicken, I am hoping to hear good news that the chicken would have had to be subject to far more adverse conditions before bacterial growth reached hazardous levels.