what i also saw was that people get chills when they have a fever yet people have chills without being ill. Getting the chills is a way of
raising the body temperature, this was another thing i read.
Physiologically speaking, the metabolic release of heat from our cells when we shiver indeed does raise the body temperature. It's a natural, heat
generating activity that happens when one is cold.
When one is ill, the body may reset it's actual set point (like your thermostat at home) to a higher level. To reach that level, your body produces
reactions that create heat; one of those things is shivering.
The body can reset it's temperature set point either from acclimation (you move to a different geographical location), from the turning of the
seasons (which is why a late summer heat wave feels hotter than it would in the middle of summer), and by illness, among other things.
Homeostasis is always sought in the body, and the body will do things to bring it's temperature to the setpoint that the metabolism sets for that
It's a fascinating process...and somewhat complicated. What I've written above is very simplified, so please be aware of that. There are all sorts
of laws and chemical issues to take into account, but the above is a very broad, general idea of how body temp works in regards to shivering.
However, since you've posted in the paranormal forum, I suspect you mean less actual shivering and more the whole "goose on your grave" or back of
the neck tingling.
Again, not taking into account any reason for it, the muscles just under the top layer of skin can actually pull on each individual hair, and raise
it. This accounts for goosebumplies as well. Those muscles are called arrector pili, and are at the base of every hair shaft in your body.
The activation of the arrector pili and it's basic reason is pretty well not understood. The best guess from most scientists are that it is a
remnant of an instinctive awareness mechanism, that would alert us to the presence of potential problems. When I hear something unexpected, I can
literally feel the hairs in my ears turning towards the sound. It's a weird feeling, but it's what happens.
Why are they triggered? It's still unknown. Could it be from a sensed presence? A "vibe"? Peripherial vision involvement? An intuition? It's
It is real. It does happen. There are sometimes physical reasons for it, and then sometimes things aren't easily explained or quantified.
As for me, I am less inclined to accept the physiological/anatomical answer as the *only* piece in this puzzle. I don't know the rest of it, but I
really, really doubt that it's just "that" and nothing else.