The best protection against injury in a tornado is a Storm shelter. However there are other actions that people can take to protect themselves..
The recommended precautions that we are familiar with include:
Going to the lowest level, away from exterior walls, in an interior closet of bathroom.
Perhaps to improve protection, we may need to examine further how people perceive these recommendations. Particularly when we know that the availability of shelters is not where we would like for it to be. For instance, should we need to assess how many single-family homes in Oklahoma actually have a "recommended safe place?"
Again, we see the data clearly supports recommendations to cover the body with thick blankets or clothing to protect against soft tissue injuries, and to protect the head and brain with a bicycle or motorcycle helmet.