Burns and cold water

[Korvan]

So I burned my arm the other day on a hot iron ring stand in a chem lab giving myself a small 2nd degree burn. I put the burn under cool water for a short time and the lab instructor insisted that I see the college's nurse after the lab. While there I was given a first aid hand out and I was surprised to see that it recommended cooling the burn for 30 minutes under cool water.

Now cooling the burn does make sense, if you get rid of the heat that caused the burn, it will prevent further damage, I get that. But there's no way a 1/10 sec contact with hot iron transfered enough heat to warrant 30 minutes under the tap. Assuming a temperature difference of 300 degrees between the iron and my arm, a temperature difference between my arm and the water of 30 degrees and with the thermal conductivities of iron and water being 80 and 0.58 respectively, we get the rate of heat transfer of the iron being about 1400 times that of water. (thank god the ring stand wasn't made of copper with thermal conductivity of 401)

So with a 1/10 of a sec contact time with the iron, 140 secs in running water should do the trick, just over 2 minutes. Now if my reflexes are slower than I guessed, say up to 0.5 sec, that jumps up to almost 12 minutes. That's a lot longer than I figured but still well short of 30 minutes. I'm guessing there might be other mechanisms at work here such as all the nasty junk from the destroyed cells causing further damage so cooling the area slows that down as well.

Just out of curiosity, if anyone know medically why such prolonged immersion is recommended or if I butchered my quick and dirty thermo calculation, I'd be interested in knowing.

(edit - The conductivity for iron I used turns out to be valid only at 25 degrees (C), it decreases as the temperature increases, becoming 60 at 225 degress (C) which is the closest value I could find. This gives a rate of heat transfer of 1000 times for iron rather than 1400 making my 0.5 sec contact time require 8.6 minutes of cold water immersion rather than 12)

[Wyrm]

1) Reduces swelling and pain. People don't like pain, and excessive swelling can sometimes cause more damage than the original injury.

2) The oils that normally protect your skin have now been boiled off. Also, you have symbiotic bacteria on your skin that work by crowding out dangerous bacteria. In a burn, these oils have been boiled away and the normal flora of your skin has also been stripped, leaving your skin more naked than naked. This poses an infection hazard as well as a danger of that patch of skin drying out, so you need to keep the area clean and moist while the oils regenerate and the good bacteria recolonize the area — after the water wash, you should cover the area with a sterile bandage. The water also washes out contaminants that may be left behind by what burned you. In your case, it's small particles of iron.

3) There's also the fact that using water is way better than using a common folk remedy for burns: covering it with butter or shortening. Using either can aggravate any number of the above.

[Broomstick]

#1 in particular - the cold water reduces swelling and the subsequent damage that can occur from your body's reaction to the burn, as well as reduce pain perception.

[Crossroads Inc.]

I have never understood where the "Cover a burn with butter or grease" came from.

As a Kid I remember watching a GI-Joe which had "Burn safety" as its little message at the end of the cartoon.
One of the points they said was "Don't put butter on it" I must have been like 11 and I thought right off the bat "Thats crazy, oil is going to hurt a burn."

I've heard countless people say "Don't put butter on a burn, its just a folk remedy" but I can't recall hearing anyone actually say that.

That said...

I do wonder if any harm can be done by keeping a burn in ice water for too long.
I've had times where I soak a burn in cold water, and I feel as though it becomes 'climatized' to the cold water.
When I pull it out after a short time, the pain of the burn comes back as though it were even more acute.

[Korvan]

Hmm, never really thought about the good bacteria being burned away. Also I don't really get why the body's natural reaction to injury can cause more damage. Intelligent design my ass! I guess burns are pretty rare in a pre-technological setting and we never evolved an efficient way of dealing with them.

[eion]

Hmm, never really thought about the good bacteria being burned away. Also I don't really get why the body's natural reaction to injury can cause more damage. Intelligent design my ass! I guess burns are pretty rare in a pre-technological setting and we never evolved an efficient way of dealing with them.

Blistering occurs to protect the skin underneath and allow it to heal more quickly. The oils burning off your skin is also a good thing. If the oil is burning, your hand isn't.

If you had a 2nd degree burn, the skin would blister almost immediatly, which is supposed to prevent further damage to the skin.

[Spectre_nz]

I do wonder if any harm can be done by keeping a burn in ice water for too long.
I've had times where I soak a burn in cold water, and I feel as though it becomes 'climatized' to the cold water.
When I pull it out after a short time, the pain of the burn comes back as though it were even more acute.

We had a nasty accident at work with an autoclave a couple of years back that burned two people, after that we had a first aid training course in case of any future accidents. The First aid nurse had a bunch of interesting burn related stories and said that most of the pain after a burn is nerves firing when in contact with air – much of the relief of the cold water is that it’s keeping the air off.
She said more than 15 minutes in water becomes counterproductive as damaged tissue can become waterlogged (somewhat different advice than Korvan received) and recommended 15 minutes in cold water, and then covering the burnt area with saran wrap to keep the air away from it. Apparently in New Zealand this is the done thing, as it reduces the pain of the burn and protects it from any air-borne bacteria. Also, it doesn't stick to the burn, like towels or clothes do.

[Rye]

I have never understood where the "Cover a burn with butter or grease" came from.

As a Kid I remember watching a GI-Joe which had "Burn safety" as its little message at the end of the cartoon.
One of the points they said was "Don't put butter on it" I must have been like 11 and I thought right off the bat "Thats crazy, oil is going to hurt a burn."

I've heard countless people say "Don't put butter on a burn, its just a folk remedy" but I can't recall hearing anyone actually say that.

That said...

I do wonder if any harm can be done by keeping a burn in ice water for too long.
I've had times where I soak a burn in cold water, and I feel as though it becomes 'climatized' to the cold water.
When I pull it out after a short time, the pain of the burn comes back as though it were even more acute.

Presumably the reasoning behind it would be to use it as a barrier to protect from infection and dehydration. In practise though, I suspect butter wouldn't be that great and you'd use a burn cream/cling film instead, after soaking it in saltwater.

[Isolder74]

They tell you to put the burn under running water for the same reason that after blanching a vegetable you drop it into ice water. Even though the source of heat has been removed, residual heat remains in the burned area and until that is fully removed, either by you shunting it away or further tissue damage. That residual heat can have a massive effect.

Consider a boiled egg. Boil it for one minute then remove to the counter. do the same with another egg and drop it into ice water. After the one on the counter has fully cooled, give it an hour, crack them open and compare how cooked they are inside.

[Losonti Tokash]

Soak in cool (not cold) water, wrap in sterile dressing, and most of the time you'll be good to go. Lots of burn ointments or whatever are actually counter productive, especially on a 2nd degree burn. Like has been said, you're trying to reduce swelling, remove as much residual heat as you can, and protect against infection.

And leave the blisters alone, for the love of god. They'll take care of themselves. Resist the urge to pop them. Please.

[Korvan]

They tell you to put the burn under running water for the same reason that after blanching a vegetable you drop it into ice water. Even though the source of heat has been removed, residual heat remains in the burned area and until that is fully removed, either by you shunting it away or further tissue damage. That residual heat can have a massive effect.

Consider a boiled egg. Boil it for one minute then remove to the counter. do the same with another egg and drop it into ice water. After the one on the counter has fully cooled, give it an hour, crack them open and compare how cooked they are inside.

Yeah, when I want steak rare, I can't let it sit for too long either. I was just surprised at just how much heat such a short contact could deliver. It seems to me instead of using cool water, a block of copper kept in the fridge (or aluminum for the budget conscious) would be much better at cooling down a burn as the thermal conductivity of copper is almost 700 times that of water. The toxicity of copper is low enough that short exposure shouldn't be a problem, even on compromised skin.

[Broomstick]

You're right, that block of copper might well work better, but access to cool/cold water is more common than access to small blocks of metal.

[Twigler]

I do wonder if any harm can be done by keeping a burn in ice water for too long.
I've had times where I soak a burn in cold water, and I feel as though it becomes 'climatized' to the cold water.
When I pull it out after a short time, the pain of the burn comes back as though it were even more acute.

Ice water is not recommended. Water around 14-16 C is best - tap water IOW. Too cold can damage the skin cells and slow down healing. This paper has a lot more detail if you're interested: http://burnaid.ryepharmaceuticals.com/t ... d_1999.pdf

I have never understood where the "Cover a burn with butter or grease" came from.

It gives some relief from the pain, which is probably how it started. But it is counter productive for healing. It retains the heat and provides an ideal Petri dish for bacteria to develop right on top of a wound.
Aloe OTOH does speed up healing.

[SirNitram]

I just remember what I was taught yeaaaars ago, and helped prevent too much damage to my dad when he got burnt. Immediately place the burn under running cool water. Not cold, not still. Running water will whip away the heat, and cool water won't damage skin.

[Isolder74]

I just remember what I was taught yeaaaars ago, and helped prevent too much damage to my dad when he got burnt. Immediately place the burn under running cool water. Not cold, not still. Running water will whip away the heat, and cool water won't damage skin.

The fastest way to thaw frozen food works in the same way. The running water works faster then simply just holding it under ice water. Of course you can only do it with meats and other foods tightly wrapped in plastic.

The speed at which to shunt away the heat can easily make the difference between a minor burn and a 2nd degree one.

[Losonti Tokash]

The speed at which to shunt away the heat can easily make the difference between a minor burn and a 2nd degree one.

What? No. By the time you're treating the injury you're working to minimize recovery time, discomfort, and risk from infection. Unless they're still on fire or something the injury isn't magically going to keep burning through their skin.

[Agent Sorchus]

The speed at which to shunt away the heat can easily make the difference between a minor burn and a 2nd degree one.

What? No. By the time you're treating the injury you're working to minimize recovery time, discomfort, and risk from infection. Unless they're still on fire or something the injury isn't magically going to keep burning through their skin.

Your wrong on this, oils in the skin boil for a long time and have high thermal mass. That boiling oil is what does the damage that differentiates second degree burns from first degree. Third degree burns do not matter, flesh is burnt away completely.

[Isolder74]

The speed at which to shunt away the heat can easily make the difference between a minor burn and a 2nd degree one.

What? No. By the time you're treating the injury you're working to minimize recovery time, discomfort, and risk from infection. Unless they're still on fire or something the injury isn't magically going to keep burning through their skin.

So little you know grasshopper.......


Haven't you ever roasted, grilled or cooked anything?

In any situation where something is being cooked, which a burn is, there is something called residual, or carry over, heat. What this means is that if you want a steak cooked say medium-rare then you need to not cook it fully to that level before you pull it as it will keep cooking for a while after you pull it.

The same if true of a burn victim. Go back up and reread my boiled egg example. It is very possible to only boil an egg for one minute pull it and have it become fully hard inside if it isn't placed in ice water immediately after you pull it.

To make a long story short it's more important to STOP the burn from continuing to do damage then it is to contain and bandage the wound. Incidentally, doing so can hold in more of the residual heat elevating the problem.

[Losonti Tokash]

The speed at which to shunt away the heat can easily make the difference between a minor burn and a 2nd degree one.

What? No. By the time you're treating the injury you're working to minimize recovery time, discomfort, and risk from infection. Unless they're still on fire or something the injury isn't magically going to keep burning through their skin.

Your wrong on this, oils in the skin boil for a long time and have high thermal mass. That boiling oil is what does the damage that differentiates second degree burns from first degree. Third degree burns do not matter, flesh is burnt away completely.

Ah, right. I spaced out and totally forgot about that. My bad.

[Korvan]

The fastest way to thaw frozen food works in the same way. The running water works faster then simply just holding it under ice water. Of course you can only do it with meats and other foods tightly wrapped in plastic.

Years ago, I remember seeing (as seen on TV) an ad for a miracle defroster which would defrost food much faster than air or water. Turns out it was just a slab of aluminum which has a much higher thermal conductivity than water, though still only half that of copper. Seeing it in action was pretty impressive, the surface of the frozen food defrosted immediately. It took longer to defrost all the way through as the thermal conductivity of the food itself became the limiting factor.

[Isolder74]

The fastest way to thaw frozen food works in the same way. The running water works faster then simply just holding it under ice water. Of course you can only do it with meats and other foods tightly wrapped in plastic.

Years ago, I remember seeing (as seen on TV) an ad for a miracle defroster which would defrost food much faster than air or water. Turns out it was just a slab of aluminum which has a much higher thermal conductivity than water, though still only half that of copper. Seeing it in action was pretty impressive, the surface of the frozen food defrosted immediately. It took longer to defrost all the way through as the thermal conductivity of the food itself became the limiting factor.

The best part of that is that a cheap aluminum sheet pan would do the same job and it can be used for something else too!!! I've seen the thing that you are talking about and the 'device' is rather silly. It isn't very big and doesn't actually speed the internal defrosting much. Placing it in tightly wrapped plastic, or ziplock bag, and running it under running cold water works better.