Dlarun and Fever Iron reinforced shields both give + Fire saves.
Dlarun should give +1 to fire saves, because of it's cold properies.
Fever iron should give +1 to cold saves, because of it's heating properties.
Bonus meme to keep dev's motivated and entertained.
Yeah, I had brought this up way back way back when those materials first became available.
On weapons, you get the fire vs ice effect.
On armor/shields, they are both a protection vs fire effect. As Zyemeth suggested, this is because of how it works (inexplicably) in the source material.