>>1270520>any suggestions?Well, something UL of course. Assuming you are a man, these are about the lightest you can get:
https://www.tangaland24.de/en/men-extrem/If you are a girl, there is much more brands to choose from.
Other than that, if you wanna something more traditional and don't care too much for the wheight,
>>1270532 is on the right track. Personally, I hate boxers, but there's also a few manufacturers making merino boxer briefs.
If you wanna go with artificial fabrics, Uniqlo has some nice (and cheap) stuff, which is 100% as good as the more expensive stuff by the big outdoor brands.
Just don't get cotton for anything that's not only single day.