Japan unveils 'human refrigerator' to combat extreme summer heat (globalsouthworld.com)

What about , planting some trees ?

or you could just dunk your elbows into some ice water

https://www.cbsnews.com/news/quick-and-cheap-cooling-solutio...

https://www.hprc-online.org/sites/default/files/2026-03/HPRC...

https://www.army.mil/article/257626/the_arm_immersion_coolin...

super high tech https://www.firstlinetech.com/core-tech/arm-immersion/

It can't be efficient to cool one person at a time