Self-Warming Vibrators

I am having quite a time researching and looking up reviews for self-warming vibrators. This is the kind that you turn on or plug in and it warms up to 40 degrees Celsius or something. Not the kind that "sustains" warmth it gets from body heat or dipping it in hot water. There are practically none of this sort online nor are there reviews on using one. Why is this? The only one I found costs about US$300 and that is waay too much for the local Chinese budget to handle. This vibrator may be considered a safety hazard being too hot and singeing off all pubic hairs. Hm...interesting notion. However, the Big Boss must have given us faulty ones to check out because they are taking forever to heat up. I need reviews on self-heating vibrators!