4 Bring up 2 sides of foil so edges meet. Seal edges, making tight 1/2-inch fold; fold again, allowing space for heat circulation and expansion. Fold other sides to seal. 5 Place packs on grill ...
While there are dedicated products available for this hack, all you need is some reflective material like tin foil, or even an inside-out crisp packet could work. Many people are keen to try anything.