Burns used to be classified as follows:
- First Degree: Skin is pink, but no fluid-filled blisters.
- Second Degree: Skin had fluid-filled blisters of varying sizes.
- Third Degree: Multiple layers of the skin are involved. There may be charring of the wound. The picture would denote, at the very least, a third degree burn.
- Fourth Degree: Charring and burning that involves muscle and bone.
Now, we refer to burns as partial thickness or full thickness. Partial thickness would include first and second degree burns. Full thickness would be considered third and fourth degree burns.
Here is a good resource that discusses the difference.
Treatment of burns depends on location, size and depth.
Very simply, localized burns are usually treated by cleaning, leaving blisters intact, slathering them with triple antibiotic ointment and then dressing them.
Not all burns need to be followed up by a specialist at a burn clinic but burns that involve the hands or feet (because of functionality), the face (for cosmetic reasons or if they could hinder the senses), or genitalia (including nipples) are usually referred for further care.
Also, burn injuries need to be estimated on what percentage of the skin is involved. Based on the percentage-- a patient can be referred for follow-up or flat out admitted if the burn injury is severe. You may have heard this referenced to as the "Rule of Nines". Pediatric patients have different ratios so keep that in mind.
Here are a few links that help estimate burn percentage based on skin area:
Most patients with significant burn injuries have significant pain. We do tend to give something that has a narcotic to help their pain. Also, based on the percentage of burned skin, some patients will also need fluid resuscitation, ICU admission, intubation--- etc, to manage the injury.
So, if you're writing about burns and your POV character is a medical professional, keep these things in mind so your character can be treated the right way with the medical professional using the right language.