Original Tip #25 - Do not lay, sleep, or have sex on bloody mattresses.
First of all, let's get this out of the way - eeeeeeewwwwwwwww!!! - Second, studies have shown that blood & gore on mattresses do not correlate well with restful sleep, and most chicks won't dig mangled human spilth as an aphrodisiac. But hell, if you come across a nastified mattress and your honest first instinct is to either lay down or bump uglies on it, then you might as well do so, because you are bound to die a torturous and gruesome death.