Just a quick thought; In long desert races some drivers wear a cooling vest that uses a small pump to send cooled water through tubes sewn into a vest. They are expensive but could be home made. One of the links sells the tubing.
https://www.roguefitness.com/techniche-elite-hybrid-cooling-vest?gclid=Cj0KCQjwsLWDBhCmARIsAPSL3_3KKec95iGskqMjR0VG4NtSHfrSk9snbA1KF6bV9hWpZ3iZChzzzhIaAr-YEALw_wcB
https://www.pegasusautoracing.com/productselection.asp?Product=CS419&utm_source=google&utm_medium=cpc&utm_campaign=CS419&gclid=Cj0KCQjwsLWDBhCmARIsAPSL3_2JlEU_Mx55rKy55X5iDM7CdFwsDWk8U3AL3_1WCyqAqW3wiLCJhXgaAmf-EALw_wcB
https://youtu.be/PqbpHUvZ9Oo
https://www.roguefitness.com/techniche-elite-hybrid-cooling-vest?gclid=Cj0KCQjwsLWDBhCmARIsAPSL3_3KKec95iGskqMjR0VG4NtSHfrSk9snbA1KF6bV9hWpZ3iZChzzzhIaAr-YEALw_wcB
https://www.pegasusautoracing.com/productselection.asp?Product=CS419&utm_source=google&utm_medium=cpc&utm_campaign=CS419&gclid=Cj0KCQjwsLWDBhCmARIsAPSL3_2JlEU_Mx55rKy55X5iDM7CdFwsDWk8U3AL3_1WCyqAqW3wiLCJhXgaAmf-EALw_wcB
https://youtu.be/PqbpHUvZ9Oo