Why do burns take so long to hurt?

Step on a tack and before the skin is broken, you’ll feel a sharp pain–even through the thickest skin. Back up onto a curling iron and your forearm will sizzle before you even realize it.

There is a time difference, no? Why?

WAG1: On the surface, your skin has a lot of water in it. Water has quite a high specific heat (meaning you’ve got to put a lot of energy in it, relative to other substances, to heat it up). It’s not until this outer layer of water in your dead epidermis layer boils away and stops protecting your live dermis layer that you begin to feel the pain.

WAG2: Because when you’re burned, it kills the nerves where it’s hot enough to cause pain. It doesn’t hurt until the nerves next to those destroyed can transmit the message.

It isn’t much of a time difference. I once received second-degree flash burns on my hand and it hurt almost immediately.

Another WAG: You only feel the heat when your flesh is heated up, by which point, you’re burned.

It’s not just burns. When I cut myself, or especially when I stub my toe, there’s a second or two in which I think, “In a second or two this is gonna hurt like hell!” then “YEEEOOOWWW!!!”

No. The sensory nerves will transmit at about the same speed. Various injuries may take various times to process and in some circumstances may take a while to register if some other major distraction is going on.

Reminds me of a joke, by Mike Royko:

Yuppie in a car accident; sobbing at the scene at the loss of his BMW. Cop to yuppie: “Why are you crying about your car? Your arm is torn off.”
Yuppie: “My Rolex! My beautiful Rolex!”

I’ve noticed that tacks seem to hurt more than nails. I’ve stepped on a nail, about 3-4 inches long that went through my foot from under my shoe. I didn’t even know I stepped on a nail. I gently pulled my foot off, no pain really. After a few hours the pain set in and lasted about a month.

Burns, I’ve noticed them immediately. All except sunburn of course, which sneaks up on you and gets you right before going to sleep.

It’s partly a mental awareness thing… I want you to try an experiment: While you’re well aware, try putting that curling iron on your arm. See if it takes a few seconds before you feel it. :stuck_out_tongue: … I’m kidding.

Cuts, punctures, burns - I notice them all immediately. I accidentally put my arm near the spout of the teakettle I keep steaming on my stove all winter (no humidifier in apartment furnaces) the other day. The kettle is barely at simmer temperature, but it was hurting even before I could snatch my arm away - which was as near instantaneously as I could manage to do that and turn to the sink to run cold water over it. Oh, but that smarted! As many years as I’ve been using that teakettle, you’d think I wouldn’t have done anything so stupid.

I don’t think everybody’s nervous system functions at the same speed. However, IANA neurologist.


As I understand it, much of the “hurting” portion of the sensation of pain is transmitted by the type of nerves called C fibers, which transmit at about 2 meters a second - slow enough for the transmission delay to be noticeable. There’s another set of nerves that transmit damage warnings faster, and give you a finer detailed feel of the damage, but don’t hurt as much if at all. Which as I understand it is why you can, say, get a cut on the finger and feel the tiny wound, but most of the finger hurts; the nerves producing the hurting sensation have really poor resolution.

So if you step on something, you’ll get the “you stepped on something sharp/hot/whatever !” message noticeable faster than you’ll get the “that hurts !” message, more noticably compared to body parts nearer the brain.

Heh, I personally prefer to rip my feet off quick, like a bandaid.

I can’t stand it. ROFLMAO


My roommate’s trying to sleep!

Well, not with your feet ripped off you can’t.

Well, now your ass and your feet are off.