UK medical cannabis is typically vaporised, not smoked, to avoid harmful toxins...

https://star-wiki.win/index.php/Why_Do_UK_Medical_Cannabis_Supply_Chains_Look_Different_from_Normal_Medicines%3F

UK medical cannabis is typically vaporised, not smoked, to avoid harmful toxins from combustion. Device type (conduction vs convection) and temperature settings influence how effectively cannabinoids are absorbed