Ecstasy is a synthetic drug, which gives people more energy. As with most drugs, it is impossible to know if the drug is pure. Ecstasy can interfere with the body’s natural mechanism which controls heat, and most deaths from ecstasy have been caused by the body overheating.
How many deaths a year are caused by ecstasy? – http://wiki.answers.com/Q/Deaths_caused_by_pneunam