I have a pot with a plastic handle. For 2 or 3 times I used it to cook things and I smelled a weird 'gassy' smell. Turns out, it wasn't a gas leakage but instead, the handle was slowly melting (though not really visible). I can smell residue of it from my hands where I held the handle. I breathed in the fumes for minutes each time. I know that plastic fumes are cancerous. How lethal were my experiences? Any advice would be much appreciated, thanks.