Made for the Cold

Goliath

You have resistance to cold damage, and are naturally adapted to extreme cold (down to an ambient temperature of –94ºF or –70ºC). Frostkin eyes are particularly sensitive and protected from reflected light and light on the higher end of the visible spectrum, helping them navigate and identify friends/foes in blinding snowstorms. They suffer no penalty to vision because of low visibility due to snow or ice. They gain advantage on Perception checks in which a target is obscured by blowing snow or ice. You can see minute differences in heat. Thermal vision allows you to see in complete darkness, with the slightest temperature differences on normal surfaces allowing you to see everything within range normally. However, anything significantly different in temperature stands out dramatically. For example, creatures are generally much brighter, the frosty cold from a spell much darker, even the footprints of a creature still freshly warm on the ground seem to glow.
However, you cannot see color, shades, or even whether something is a matte, satin, or shiny surface with thermal vision. You see shapes and three-dimensional textures at normal levels of detail. A commonly applied weakness of thermal vision, for example, is a total inability to see writing on paper or parchment, or symbols painted on signs.
What differences in heat or cold from the surroundings are visible is determined by the DM.
You also gain advantage on Intelligence (Investigation), Wisdom Perception), and Wisdom (Survival) checks that rely on sensing differences in temperature.