Is there a way to get rid of heat rash?

I chose hiking for a mid-summer trip, and as a result, my chubby legs got chafed and I developed heat rash.

My skin is on the sensitive side, and I get heat rash...

My skin is sunburned... and I have many scars of glory...

-4kg by the end of the trip due to hiking every day

I'm happy that I've lost weight, but my body is stinging haha.

The fat in the greenhouse is helpless against heat rash.

It's been so long since I've had heat rash, and I don't know what to do. How can I get rid of this?