# The Chill. **URL:** \ **Category:** Factual Questions\ **Created:** [April 9, 2002, 4:08am UTC](https://boards.straightdope.com/t/the-chill/102617 "2002-04-09T04:08:30Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Jim\_B](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jim_b/32/4338_2.png) [@Jim\_B](https://boards.straightdope.com/u/Jim_B)\ **Post date:** [April 9, 2002, 4:08am UTC](https://boards.straightdope.com/t/the-chill/102617/1 "2002-04-09T04:08:30Z")
What is it when you hear the national anthem, etc. and you feel a _“chill”_ run down you back. I sometimes feel “needles” on my face too. _What is it?_ Incidentally, I did have this as part of a two-part question on the old SDMB. But as far as I know, this particular question was never answered. TTFN:D ---
**Author:** ![cynic](https://avatars.discourse-cdn.com/v4/letter/c/e95f7d/32.png) [@cynic](https://boards.straightdope.com/u/cynic)\ **Post date:** [April 9, 2002, 5:43am UTC](https://boards.straightdope.com/t/the-chill/102617/2 "2002-04-09T05:43:15Z")
I believe it’s due to vestigial remains of the _piloerector reflex_, which would have “fluffed up” the hair of our furrier ancestors, making them appear larger and more formidable as part of the sympathetic nervous system’s “fight or flight” response, but only produces goosebumps in modern humans. Just a guess, though. ---
**Author:** ![RM\_Mentock](https://avatars.discourse-cdn.com/v4/letter/r/e274bd/32.png) [@RM\_Mentock](https://boards.straightdope.com/u/RM_Mentock)\ **Post date:** [April 9, 2002, 7:41am UTC](https://boards.straightdope.com/t/the-chill/102617/3 "2002-04-09T07:41:00Z")
I’m guessing your name on the old SDMB was not Jim B.? ---
**Author:** ![Jim\_B](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jim_b/32/4338_2.png) [@Jim\_B](https://boards.straightdope.com/u/Jim_B)\ **Post date:** [April 18, 2002, 4:50am UTC](https://boards.straightdope.com/t/the-chill/102617/4 "2002-04-18T04:50:34Z")
I’m not sure it is the piloerector reflex for the simple reason there is no _visible_ effect from feeling the chill. It seems (to me at least) that when it happens, all your nerve cells seem to be firing at once. Could that have something to do with it? Just guessing of course. BFN:) ---
**Author:** ![Jim\_B](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jim_b/32/4338_2.png) [@Jim\_B](https://boards.straightdope.com/u/Jim_B)\ **Post date:** [April 18, 2002, 5:15am UTC](https://boards.straightdope.com/t/the-chill/102617/5 "2002-04-18T05:15:51Z")
What happened to my thread? First it seemed I couldn’t get a reply thread posted. I tried several times–fortunately, I didn’t end up with several duplicate threads! Now, I add a reply thread, which I thought would bring my original thread to the top of the list. But it hasn’t. Why? Oh, well. 🙂 ---
**Author:** ![cynic](https://avatars.discourse-cdn.com/v4/letter/c/e95f7d/32.png) [@cynic](https://boards.straightdope.com/u/cynic)\ **Post date:** [April 18, 2002, 9:42pm UTC](https://boards.straightdope.com/t/the-chill/102617/6 "2002-04-18T21:42:21Z")
> [@](#): > > \*Originally posted by Jim B. \* > \*\*I’m not sure it is the piloerector reflex for the simple reason there is no _visible_ effect from feeling the chill. > \*\* I’m thinking that it’s due to piloerection because the response is frequently referred to as having “chills” sent down your spine. The reason you’re calling it “chills” is not because you feel _cold_, it’s because it creates the same _sensation_ as the one you might have when cold. Piloerection stands hair follicles up on their ends, thereby increasing the amount of skin friction drag. The resulting thermal boundary layer reduces convective heat transfer and traps warm air close to the skin, producing a slight warming effect. Perhaps not very effective in modern humans, but probably useful for our ancestors. I think some people do experience piloerector reflex during patriotic moments. I’ve heard people say _“it made the hair on the back of my neck stand up”_ during such events. Maybe patriotism is just your body’s way of gearing itself up for a fight.