On the Bus

I'm on the bus to hike, with my hiking club friends.

It's so hot today that, I wish there were cool streams in the mountains.

I'm on the bus to hike,the trail with my hiking club friends.

I'm on the bus on my way to hike, with my hiking club friends.

I'm on the bus on the way to hike, with my hiking club friends.

I'm ontaking the bus to a hike,ing spot with my friends from the hiking club friends.

Could also say "I'm going to a hiking spot with my friends from the hiking club. We're taking the bus."

It's so hot today that, I wish there were cool streams ito cool off in on the mountains.

Your sentence isn't incorrect, it just has a strange flow (to me). A comma (or a period) helps, because your sentence has two separate thoughts: 1. It's hot today, so 2. I wish there were a way to cool off on my hike today.

Could also say "On a hot day like today, I really wish there were streams to cool off in on the mountains."