This hike will go overnight (a few hours if you're not camping) with an undescribable sunset and sunrise. The hiking can be difficult depending on the amount of gear you take and check with the local authorities to make sure camping is allowed.
Start in the early morning by taking the cable way (either from Leukerbad or Flaschen valley station) to Rinderhütte.
The trail from Rinderhütte to Torrenthorn is nicely done and well marked so you won't need to climb. However, depending on the amount of gear you have in your backpack it can be quite exhausting! You will not be able to see the actual peak until you reach the fore summit. The rest is a picnic!
Once you made it to the peak, head back down and enjoy the moment, especially Weisshorn and Matterhorn are beautiful to look at.
Not to overstate the obvious, but this trip shouldn't be done in bad conditions (thunderstorms can always occur in summer) and it can get very windy and cold.
Coordinates for valley station: 46.373830, 7.629066