The Knuckleball™ is a hardy little tool, but we all have our limits.
Heat is a no no! The PLA component of the knuckleball will soften around 185°F. Most of us don’t walk around in an oven so this is usually not a problem. Even the inside of a parked car only gets up to around 113°F on the hottest of summer days.
Avoid the urge to put your Knuckleball™ in the dishwasher please!
Otherwise, you want to keep your Knuckleball™ away from solvents such as hot benzene, tetrahydrofuran, dioxane, dichloromethane, and etheylacetate in the off chance that you work in a chemistry lab.