The death of a student who took ecstasy as a “final fling” following the end of her university exams has prompted a pathologist to warn young people against fooling themselves into believing they are immortal.Joana Burns was with a group of friends celebrating the end of her final year of a maths degree at Sheffield Hallam University when she took £7 worth of the drug.Miss Burns rolled the powdered drug, also known as MDMA, into ‘bombs’ and took one before she went into the union building on June 6 last year.But after taking another bomb in the early hours of the morning the 22-year-old vomited it straight back up and began fitting before being rushed to hospital, where she later died.Pathologist Kim Suvarna told an inquest into her death on Wednesday that Miss Burns died from drug toxicity after the MDMA reacted with enzymes in her body, causing it to overheat.Dr Suvarna, a Consultant Histopathologist at Sheffield Teaching Hospitals, said people up and down the country, like Miss Burns and her friends, take the drug without paying too much thought to the dangers.But he added: “There’s no such thing as a safe drug, particularly with this kind of psychoactive substance. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings. “If you are susceptible, they will kill you. The young tend to believe they can do things they wish because they are young and immortal. Unfortunately, that doesn’t apply.”Lewis Birch, Miss Burns’s boyfriend, told the hearing at Sheffield Coroner’s Court that she had taken the ecstasy willingly and he thought it was probably the third time she had done so.He said they were with a group who decided to go to the Tuesday Club at Sheffield University students’ union – an event he said was known for the use of ecstasy.Mr Birch said he had paid £14 for two quarters of ecstasy – cheaper than the price he had previously paid – and that nobody else who took the drug in the group suffered any adverse effects.There had been reports at the time of Miss Burns’ death that one of her friends had also collapsed.Mr Birch, a former biomedical sciences student who said he had been in a relationship with Miss Burns for three years, said the group had decided to go out that night as a last celebration of their time at university.The night out was described by Detective Constable Elizabeth Cooper, who investigated Miss Burns’ death, as a “final fling”. Assistant coroner Abigail Combes recorded a verdict of misadventure.Following the inquest Miss Burns’s mother Mosca Burns, from Alfreton, Derbyshire, urged youngsters to resist the temptation to experiment with drugs.Speaking outside court she said: “I would prefer it if nobody took MDMA again because I don’t really think you can assess the risk.”It’s different every time you take it. It can have a different effect on your body, it’s made in different ways, in different recipes, in different places, by different people, with different ethics. So, it’s not worth the risk.”Mrs Burns has previously expressed the hope that her daughter, who wanted to be a maths teacher, would be remembered more as an inspiration for girls to take up maths rather than as another victim of illegal drugs.