There is some evidence that cancer can be initiated by constant irritation of body surfaces (like skin and the lining of the mouth and throat). Extremely hot water can serve as this constant irritant. Research has shown that the way in which mate, a herb based infusion drink consumed almost exclusively in South America, is drunk can increase risk of oesophageal cancer (the oesophagus connects the mouth with the stomach.) mate is drunk with a metal straw which is left in the mouth like a tobacco pipe. This combined with extremely hot water results in a constant ‘assault’ to the lining of the throat. There is very limited evidence of similar effects with tea and coffee drinkers based on the most common means of consumption.