These cards change with the depth you pick above.
Pain is a message sent by nerve endings (free nerve endings and other sensory receptors) in the dermis. In first- and second-degree burns these endings are irritated but still alive, so they fire hard. That is why a blistered burn hurts so much.
A full-thickness (third-degree) burn destroys the whole dermis, nerve endings included. With no receptors left, the centre goes numb. The edges are shallower, so they still hurt.
Fluid balance. Intact skin keeps water in. Burned capillaries leak plasma, and the open wound lets water evaporate. A large burn can cause dehydration, electrolyte imbalance and even shock or kidney failure.
Temperature control. Burned skin cannot sweat or adjust blood flow normally, and wet wounds lose heat by evaporation. Patients can get dangerously cold.
Infection defence. The epidermis is a physical barrier. Once it is gone, bacteria can get in, and dead burned tissue (eschar) has no blood supply to bring immune cells.
1. What degree is this burn?
Tap any region to shade it. Each figure is split into front and back halves, so you can pick just the front of an arm (4.5%).
After a big burn, fluid pours out of leaky capillaries. Replacing it fast prevents shock. The Parkland formula estimates how much IV fluid (lactated Ringer's) to give in the first 24 hours.
It is only an estimate: the actual rate is adjusted hour by hour based on the patient's urine output, and local protocols vary.
Enter your answers, then check. Each has a worked answer.