Among the new outfits added in the extension of the champion’s Ballad of Zelda Breath of the Wild, you will be able to retrieve The Island Lobster Shirt that is part of the side quest EX Treasure Gard of Winds. The Island Lobster Shirt provides heat protection to Link when fitted.
According to the equipment description :
The Hero of Winds once wore this shirt on the quaint island he callde home. They say he wielded the wind to travel the ocean wide. It’s a rather rare find (referring to Zelda Wind Waker).
Where is the treasure of Gard of Winds / The Island Lobster Shirt in Zelda Breath of the Wild:
To get this tunic, first teleport to the lake tower and then drop from the tower to reach Cora Lake, which is just below the tower. In this lake you will find an EX submerged chest by positioning yourself against the counterflow of the water. The chest contains The Island Lobster Shirt (see screenshots for the precise position of the chest).
Take out your Cryonis power and create blocks of ice in the water to get as close as possible to the chest EX. Then take out your Rune Magnesis and pull the box out of the water to grab The Island Lobster Shirt and finish the EX quest for the Gard of Winds.