The backstory of one of my characters involves being lowered onto steadily rising, open flames back first. The story is set in a dystopic/post apocalyptic time where modern technology became unavailable over a hundred years before this time, so skin grafting, sedatives, and medical tools are all absent from the equation. The only supplies they have for healing would be herbs, fresh water, and maybe something like store bought honey that has an indefinite expiry date. For the story, the burn would have to be enough to leave the character with PTSD and a massive scar as it is a big part in the plot-line. Would it be possible with the situation described for my character to survive by healing and fighting infection with herbs and fresh water?
Assuming no inhalation and it is just their back that is burned it is completely possible for them to survive especially with care, some form of care is importance as the victim will not be moving around much. By care I mean someone to clean the victim, change bandages, and feed the victim. Likewise scar tissue that extensive will hinder mobility even after it is healed. You do need to consider how severe the burn is, if there's a lot of muscle damage they may have severe mobility issues, and it is far more likely to kill them. You may want to limit your burns to reaching the fatty tissue and not down to the muscle.
For reference their back would be 9-18% of their body surface depending on how much of the lower back is burned, so survivability is still fairly good.
Boiled water would be better than fresh for cleaning and honey or snail slime and bandages would be an acceptable/believable covering. More on the history of burn treatment here. Fluid loss is a big factor so they will need a lot of water.
People in the old days treated burns all the time. Just as now, the outcome depends on the amount of skin burned, the area burned and the health of the patient.
I am a big fan of Ambroise Pare, "the father of surgery". He lived from 1510 to 1590.
I then told him [Sylvius] this story about a kitchen boy of monsieur le Marshal de Montejan who fell into a cauldron of almost boiling oil. When this happened I was sent for and at once went to ask an apothecary for the refrigerant medicines that one was accustomed to apply to burns. A good old village woman, hearing that I was speaking of this burn, advised me to apply, for the first dressing, (for fear that pustules or blisters would result), raw onions crushed with a little salt; I asked the old woman if she had used this in the past and she answered, in her dialect, ‘Yes, sir, by God’s faith’. Then I was agreeable to trying the experiment on this kitchen scullion; and, truly, the next day, the places where the onions had been had no blisters or pustules, and where they had not been all was blistered. Some time later a German of the guard of the said seigneur de Montejan was very drunk and his flask caught fire and caused great damage to his hands and face, and I was called to dress him. I applied onions to one half of his face and the usual remedies to the other. At the second dressing I found the side where I had applied the onions to have no blisters nor scarring and the other side to be all blistered; and so I planned to write about the effects of these onions.
The striking feature of the account is the comparison between the effects of onions and those of other treatments. In the first case, of the scullion, we are told only that in the places where the onion paste was not used there were blisters, but there were none where it had been applied. One supposes that this opportunity for comparison of treated and untreated areas probably arose as a chance effect of how the onion paste was applied. But in the second case, of the soldier whose powder flask had gone on fire, Pare´ records that he quite intentionally treated one side of the burnt face with onions and the other with ‘the usual remedies’ and that there was a very marked difference between their effects.
Another effective treatment for burns available in pre-technological days is honey. Astonishingly, honey works well!
I am not sure how old this use of honey is. Certainly people have been collecting, eating and fermenting honey for a long time.
So the answer is yes: people are amazingly durable, and folk remedies are often better than nothing.
Depending on the amount of skin involved it's possible to survive. Third degree burns are usually painless since even the nerves end up burned and no message of pain reaches the brain at first.
You will end up useless for months until someone could remove all the burned flesh to allow healing and growth of new skin completely. During the process you can't usually move or sweat for the pain and the danger of infection that would kill you in days.
Old remedies, folk remedies, historic remedies, got to be that way becuase they did work. Even odd things like blood letting, leaching, etc. worked to one degree or another.
The opening of the superficial vessels for the purpose of extracting blood constitutes one of the most common operations of the practitioner. The principal results, which we effect by it, are 1st. The diminution of the mass of the blood, by which the overloaded capillary or larger vessels of some affected part may be relieved; 2. The modification of the force and frequency of the heart's action; 3. A change in the composition of the blood, rendering it less stimulating; the proportion of serum becoming increased after bleeding, in consequence of its being reproduced with greater facility than the other elements of the blood; 4. The production of syncope, for the purpose of effecting a sudden general relaxation of the system; and, 5. The derivation, or drawing as it is alleged, of the force of the circulation from some of the internal organs, towards the open outlet of the superficial vessel. These indications may be fulfilled by opening either a vein or an artery.
We may laugh or count these out today, and they may not have been the cure all that history's actors seem to think they were, but healers were caller "healers" because they actually healed. It may be primitive, but in many way's it did work. In some way, some things, work better then the solutions we use today. Keep that in mind when you do your story.
Now with burns there are 4 major problems you need to address. 3 of which the "cure" hasn't changed in a very long time.
Mobility. The loss of skin will make mobility very rough. Even something as simple as turning over will cause pain and perhaps prolong the healing process. Just like today, the best cure seems to be sedation, rest, and people to help out with care. I lone person would have a hard time, but a person with a team of people to help out would fair pretty well here.
Hydration. Burns cause serious use of the bodies water reserve. That reserve needs to be replaced. Today with extreme cases the water being replaced is more then the body can naturally absorb. Because you only talking about 10%-15% of the body your person should be able to drink enough water and eat enough broth to stay alive. Again a team of people will help a lot. To be fair the biggest impact is on blood volume. It takes time to make blood, but we can call this hydration, and liquid intake is the most important step making blood. The body can probably provide the rest.
Heat regulation. Specifically, with a large patch of skin damaged you risk Hypothermia. It could be 90 degrees out and you will freeze to death as a large part to the bodies radiator is malfunctioning. Again the "cure" hasn't changed much. Keep the person warm. Maybe even uncomfortably so.
Infection. This is the one that has changed a lot. Today antibiotics, false skins, better bandages, creams and what not can do an amazing job at fighting infections. However at the tech level your talking about, antibiotics were not exactly well known. There are a ton of natural things that can help though. Honey, Oils, thyme/orgeno, and many other things can really help. Honey is probably the best and easiest to get, but Olive oil can be used as well. Spices and herbs need to be miked into a poultice or distilled into essential oils. The big problem here is that it's gonna take a lot, and it's going to be hard to apply. The burn ill need to be cleaned but without preventing skin growth, and the whatever applied without causing more damage. This will not be plesent.
Even in history, people could survive 3rd degree burns. The scaring would be pretty bad without our newer ways to speed up the regrowth of skin (like grafting and temp artificial skin). But it's possible to live though. The person would have some mobility issues and a very disfigured back. Though if the burn were in the right spot, our back skin doesn't move too much. The healing process would take a very long time and a lot of resources. But it is doable.
As to PTSD. I don't think the actual getting of the burn would be that scary. But the healing process would certainly be. We are most scared when we have no control. And to heal this would the person would need to give up, or have control taken, for a very long period of time.
Most people could not survive, not because the availability of ways to treat the problem but because of the shear amount of time and effort it takes. A father that got burned for example would need to make his family miss 1-2 harvests just so they can provide care to heal him. His entire family would die if they went that route, so the children would "work the field" and he would try to care for him self, resulting in care that would not save him.
Same is true in towns and villages. Without a lot of the supporting tech we have today, each member of the village has to pull their own weight. The kind of around-the-clock care that a burn like that would take just isn't available to most people. Were talking about 2-3 dedicated people doing nothing but tending to this one person. That's 4 people's food, heat, wood, housing, and what not that someone needs to absorb.
Your best bet is a young male, late teens. Early enough that his rich parents are still providing for him, but old enough to be able to survive the burn. 16-18 should do. Women need not apply, history shows us that we don't waste those kinds of resources on women. (keep in mind that "history" here is because the people with enough money to do such a thing, want sons to carry on the family name).
You also need a real reason to want to have the boy. A prophecy. The only son of a rich man that can't make more children. Selling the boy to someone for more riches maybe. It would help if the reason made sense to the entire village and not just the parents.
Get your victim to a sage immediately. Let the sage cover the wound completely with honey, cover it with a (sheep) skin soaked in rendered fat to make it waterproof (we use cling wrap at home) and bind it on with something to keep it in place. The sage will insist that the victim stay mobile: this is Important if you want to preserve full mobility! The honey is never washed off until the burn is completely healed! Have the sage open the dressing and add more honey on a 48-hourly basis, then cover it with a clean, fat-covered skin.
The one drawback here is that it may heal up so completely that there is no scarring. If the victim only made it to the sage once the burn had dried out, he could possibly suffer loss of some mobility and have scars, but I won't personally guarantee it.
I have personally used this protocol to reverse my own right thumb, which had become necrotic after a snake bite and to completely heal my wife's right forefinger after it had been burned to the bone by a lump of white-hot metal. Although the metal removed a piece of her finger about 1/2" in diameter, right down to the bone, the honey treatment healed it so completely that you can only detect which finger had been burned with very careful examination.
One other thing: application of honey to (especially) burn wounds brings such relief that analgesics (pain-killers) is rarely necessary. The main reason that medical science can find no "real" value in the use of honey for burns and other wounds is their obsession with what they call "sterility". They keep washing the honey off and thus breaking the antiseptic barrier made by the honey. If left undisturbed on the wound, the honey excludes all sepsis-causing agencies by releasing hydrogen peroxide. It also absorbs the fluids (plasma) exuded by the burned tissue and allows it to be reabsorbed by the damaged flesh. As it keeps the burn moist, the flesh is regenerated and if the victim remains mobile, so will the new flesh and skin also regain its natural elasticity. As stated earlier, scarring will be minimal, and although the new skin will be lighter in colour than the surrounding tissue, it will regain its normal colour in time, leaving only a thin line around the periphery to show that anything untoward has happened.
Yes. I had a friend whose sister was badly burned by a gasoline fire (she poured it in to the fireplace) back before penicillin etal. She wasn't expected to survive. She spent a year in the hospital where basically all they did was drug her. When she didn't die, they eventually turned her out. Her skin from her chin had grown to her chest, they had her head tilted up the entire time. Her sister had very stiff, rigid skin and couldn't raise her head or arms due to the tissue issues. But live she did for almost twenty more years.