The first device to be applied is a cervical collar, commonly called a "C-collar."
The c-collar can be omitted. They are marginal performers at best, and improvised c-collars are likely to be worse than useless. This is one thing a SAM splint cannot do.
Excellent post Jeff.
Although less than ideal*, the SAM splint can actually be used to improvise a reasonable c-collar in the absence of an actual device. This
link shows the wrap technique to fashion one in the field - scroll down to the tenth video to view.
Jim
*The SAM video shows the PT's head being moved around a lot more than one would ever like to see, although this could be somewhat minimized if the c-collar were to be fashioned while the PT was in the supine position.