[thatcat]

Heat is well known to cause cancer, including in the form of hot beverages; but the contents of smoke aside from CO2 and H2O depends entirely on the source of combustion.

[dTal]

I'd not heard this about heat. It doesn't seem like an entirely straightforward link to me - aren't saunas supposed to fight cancer?

[thatcat]

Since cancer is caused by certain mutations and heat can induce mutation, ingesting hot things can be mutagenic and thus carcinogenic.[0]

Saunas at the right temp for the right time can induce the expression of protective heat shock protiens.[1]

[0]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2773211/

[1]https://www.selfhacked.com/blog/reasons-sweating-far-often/