Is there any supplement to help a child who get's over-heated easily?

[Guest guest]

My friend has a son with autism who always get's over-heated easily when outside

in the sun. We went to the zoo the other day with them, and they had to cut

their day short because he got over heated. He gets red cheeks, sweaty and

although we can get in the shade and go into air conditioned gift shops, he

still reaches a point that he has to go home.

Any suggestions on this?

Eileen