Mount Hylia is located behind the Temple of Time through a large stone gate. Conveniently, there are several plants that grow spicy peppers allowing Link to cook them into meals to gain cold resistance (though they won't do this on their own) and survive the below-zero temperatures. Beyond the gate is a large river known as the River of the Dead, which is so cold that Link will rapidly lose health regardless of any cold protection as it presumably soaks into Link's clothes. On the shore of the river is the remains of a building, possibly a cottage someone resided in or a maintenance shed. Inside the area where the building was is a supply of wood, possibly to fuel the fireplace before the building's destruction. The remains of a guardian is seen nearby, implying that it was the cause of the hut's destruction. A jetty with the front part missing stretches across the river, requiring Link to use Magnesis on a metal door to use as a bridge.
On the way up the mountain, Link will encounter Bokoblin camps, snowball ambushes and a cold pond but after braving all of these he will find the Keh Namut Shrine, which grants relief from the cold as long as Link's inside of it.