Laboratory rats are normally kept in either plastic or metal cages. The two
types differ greatly in the way rats are able to dissipate heat. With all
other factors identical when given MDMA, Aluminium floors enabled rats to
regulate their core temperature when they were unable to do so on acrylic
floors. This is explained by conductive heat transfer between rat and
This paper may imply that past research results on MDMA toxicity (and other
trials) depends on the type of cages used.