Aloe Vera would be better than coconut oil
Coconut oil locks in heat if you think about it we cook with it so it might not be the best thing to put on a heat rash
Calamine lotion could help too or cold compresses to the section and air drying

@eryka616, yea ive tried it a couple of times ill keep using thanks

@jgarciamua, you could try coconut oil

My son has had a heat rash in his but cheek now its on his chest ☹️ its so hot here @eryka616,

Just keep him dry and cool it should go away