I already have a sweat rash under my armpits.

Since last year, the area just below my armpits has been the softest part, so I developed heat rash and suffered from soreness.

This year, I also developed heat rash in the same area.

It's not even a baby, but I can't stand the burning and pain.

At home, I cool it with ice and also apply aloe vera gel, but does anyone know what is best to do during outdoor activities?