It makes sense, but, it's better to say: "Elephants use their body hair to regulate their temperature under the hot African sun," or "Elephants use their body hair to keep themselves cool under the hot African sun."

You can use "so that" + a clause to make your sentence clearer: Elephants use their body hair so that their body heat does not rise under the hot African sun.

Thank you all! I was really struggling with this one. I've chosen Ariana's suggestion because she has also avoided the repetition of "body". I have to write summeries for some university tasks and I must use synonymous, it's very tough for me [emoji]