Batalista's Passport

Batalista's Passport is a ring which offers 40% protection against all kinds of fire damage from weapons, spell, arrows, potions and traps. This ring can be found somewhere in the second part of the Underground Passages of Candlekeep in chapter 6. This is the only item that offers fire protection and can be worn by any character, unlike Mage Robe of Fire Resistance and the Moonblade.

In-game description
"Ring of fire resistance: 'Batalista's Passport'. The grand mage Batalista intended this item to aid in his travels in the plane of fire, and it is said he repeatedly summoned a Salamander from that realm to aid in the construction. Not being known for their patience, it is likely he should not have pestered his instructor quite so much. The finger bearing the finished ring was untouched by the inferno that claimed his tower. Had that finger still been attached, Batalista himself might have fared better."