fumes are bad but plastic has a rather high melting temp if i remember correctly
You won't reach it's boiling point, but you don't have to for some fumes to be released. Heating it up to any temperature will release some fumes and plastic particles, which when built up over extended use, aren't good for the body.
He'd have to be melting it thoroughly or smoking it constantly to get say, carbon monoxide poisoning, but he could still cause damage to his lungs or impact his ability for his blood to carry oxygen.
Probably a bigger risk is the chance of inhaling burning leaf matter, as well as any fungal or bacterial cells on the leaf.
And it's the middle of winter, so he certainly wouldn't be finding Oak leaves on a tree, so he'd be picking up semi-rotted leaves off of the ground, which besides the bacteria breaking them down, could also be covered in dirt from the ground (including animal faeces) and been trodden on by who knows what.
But all the more likely, is this is just bullstuff and he's just whoring for attention.
