The provided reference information addresses the internal temperature of a cooked burger patty, not a frozen one. The internal temperature of a frozen burger patty will be at or below freezing (32°F or 0°C). The precise temperature depends on the freezer's setting and how long the patty has been frozen. To be considered safely frozen, a burger patty's internal temperature will be well below the freezing point of water.
Essentially, a frozen burger patty's internal temperature is wherever your freezer keeps things (likely around 0°F or -18°C). It's not a specific target temperature like with cooking.
