Chromatic Shield

You call upon your connection to the myriad elemental planes to manifest a thick mass of chromatic energy around a willing creature within range as a shield. Roll 2d8. If any two dice roll for the same value ("doubles", for example 2 and 2, or 7 and 7) then roll an additional 2d8. The target gains temporary hit points equal to the sum of all dice rolled, expiring on a short or long rest. 

You may cast this spell as a second level spell or higher, adding an additional 1d8 to the initial roll for each spell level above one.