yes it can needs to be kept at body temp.
Testing positive for marijuana has a lot of different factors, from the amount of consumption , potency of the marijuana to height and weight. There are things you can do to help rid the body of THC if being tested regular like eating a high fiber diet, taking a fiber additive such as Metamucil( makes the metabolites cling to the fiber and send it out the back door). Taking vitamin b-12 ( no not niacin but b-12) helps add creatine to the body if you must dilute. There are many factors in doing things to help prepare for a random test.