Pretty severe burn requiring intraarterial calcium as part of the treatment:

A 45-year-old healthy man was involved in demolishing an industrial plant in which glass had been etched. He was exposed to a reservoir of 70% hydrofluoric acid while repairing a pipeline. He was admitted to the intensive care unit for second-degree and third-degree burns from hydrofluoric acid affecting 30% of his body-surface area, including both hands, both forearms, the chest, back, scalp, and neck. After penetrating tissue, hydrofluoric acid dissociates into hydrogen and fluoride ions, of which particularly fluoride is toxic. Since fluoride ions are inactivated by means of precipitation with calcium and magnesium, the infusion of calcium and magnesium is considered a therapy in patients with hydrofluoric acid burns. In this patient, magnesium was infused intravenously, and calcium was infused intravenously and intraarterially (through the brachial artery) and was applied topically to the burned skin.

(image via NEJM)