There are so many different armor pieces that you can find in The Legend of Zelda: Tears of the Kingdom. Just about everyone has a different specialty to it for surviving various climates. For the Gerudo Desert, you will need to keep in mind the temperature constantly, whether it is the freezing nights or blistering days. You will want the Desert Voe Trousers for those daytime sessions. Here is where to find and buy the Desert Voe Trousers in Zelda Tears of the Kingdom.
Where To Find the Desert Voe Trousers in Zelda Tears of the Kingdom

To get the Desert Voe Trousers in Tears of the Kingdom, you must get into the Gerudo Secret Club. The first time you do this, you must travel through the underground tunnels below Gerudo Town and use Ascend to pop into the store. Be sure to break the wooden crate blocking the front door so you can use that to get here in the future.
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How To Get Into the Gerudo Secret Club in Zelda Tears of the Kingdom
Once you are in the Secret Club, you can find the Desert Voe Trousers to the right of the service counter. They will run you back 650 Rupees, which is pretty cheap for armor in Tears of the Kingdom. Most items will be over 1,000, so you are getting a good deal on this particular item. If you are a little short, just sell materials or meals to the worker behind the counter.
After you own the Trousers, wearing them will give you a level of heat resistance. Unfortunately, they will not fully protect you from the sun in the Gerudo Desert during the day on their own. For full protection, you will either need to buy an additional armor piece that gives heat resistance or eat a meal that gives you the effect for a limited amount of time.
The Trousers are a part of the Desert Voe armor set. Wearing them alongside the Desert Voe Spaulder and Desert Voe Headband will give you shock resistance when all items are upgraded to at least level two at a Great Fairy. Doing so will set you back various materials that work to cool you down, so spend time gathering those items in the Hebra region in the northwest.
Once you understand how to survive the desert heat in The Legend of Zelda: Tears of the Kingdom, you will be set to explore this area at your leisure. Buying armor items that give you heat resistance is better for the long haul than relying on the timers from eating food.