Covering Shield (Combat)Source Dragonslayer's Handbook pg. 24 (Amazon)
You can use your shield to
protect your most vulnerable
parts from area effects.
Prerequisites: Dex 13, Shield
Focus, Shield Proficiency.
Benefit: While using a shield of the type
to which your Shield Focus feat applies, you
gain a bonus on Reflex saves against area of effect
attacks equal to your shield’s base bonus to armor class
plus any bonuses granted by feats or class abilities. This
does not transfer any enhancement bonuses on a shield
to Reflex saves.Source Armor Master's Handbook pg. 20 (Amazon)
You can spend 3 stamina points to also gain the enhancement bonus of your shield on your Reflex save against one attack or hazard. (Dragonslayer’s Handbook 24)