Miscellaneous, unique
This magic item appears as a glass bulb mounted in a metal frame with a silk cord attached. Pulling the cord toggles the bulb between it's On and Off states. When On the bulb sheds bright light in a 30 foot radius and dim light for an additional 30 feet. When On the bulb also begins to heat, and within 5 minutes is hot enough to require a Dexterity saving throw (DC 11) to avoid 1d4 fire damage from touching it; the saving throw is automatic for creatures with Fire Resistance. When turned off, the bulb will cool sufficiently in 1 minute to no longer be able to cause damage, and in 3 minutes will be at room temperature. The heat is insufficient to serve as an ignition source except for highly volatile compounds (much more reactive than gunpowder, for example).
If a hot bulb is exposed to Cold damage it will explode. The bulb may also be exploded if it takes takes more than 3 hit points damage of any kind, or if it is deliberately thrown to break by its holder. If the bulb explodes, all creatures within a 10 foot radius must make a Dexterity saving throw against DC 11 or take 1d4 radiant damage; creatures that cannot see, or are in the blinded condition, or resistant to radiant damage automatically succeed.
The bulb may be mounted as the light source in a lantern.