In November 1942, the Italian cyclist Fausto Coppi took "seven packets of amphetamine" to beat the world hour record on the track.  In 1960, the Danish rider Knud Enemark Jensen collapsed during the 100 km team time trial at the Olympic Games in Rome and died later in hospital. The autopsy showed he had taken amphetamine and another drug, Ronicol , which dilates the blood vessels. The chairman of the Dutch cycling federation, Piet van Dijk, said of Rome that "dope – whole cartloads – [were] used in such royal quantities." 
As a second example of the difficulties in establishing causality, consider the relationship between cigarette smoking and lung cancer. In 1964 the United States’ Surgeon General issued a report claiming that cigarette smoking causes lung cancer. Unfortunately, according to Pearl the evidence in the report was based primarily on correlations between cigarette smoking and lung cancer. As a result the report came under attack not just by tobacco companies, but also by some of the world’s most prominent statisticians, including the great Ronald Fisher . They claimed that there could be a hidden factor – maybe some kind of genetic factor – which caused both lung cancer and people to want to smoke (., nicotine craving). If that was true, then while smoking and lung cancer would be correlated, the decision to smoke or not smoke would have no impact on whether you got lung cancer.
The start and end temperatures within the flask should be established by agitating the flask and water until a constant value is reached. The test should be completed when the water temperature reaches 80o C. If the temperature is hotter or localised boiling occurs, energy will be lost in the form of steam venting from the flask and misleading results obtained. To avoid this the flask should be constantly, but gently agitated during the course of the test, and preferably the test completed before rather than after the 80o C limit is reached. It will be found that the effects of agitation following the test will tend to result in an increased temperature rather than a lowering. The use of a sheathed temperature sensing probe results in a relatively slow response time for small changes in temperature and time must be allowed for the sensor to stabilise.