Are "Hot Hands" handwarmers too hot for quick fix

Yes, I have tried the search button, but have yet to get a definate answer.

Are there any differences between the warmers that the synthetic urine companies (like quick fix, whizzinator, urinator, etc) any different than the "Hot Hands" hand warmers. Like do they contain more or less "chemicals" or charcoal so that they keep the urine closer to human temp and dont overheat. I havent had a chance to practice with them yet so any help would be nice. Hot Hands is the brand I bought and if anyone has any experience using this brand to heat there synthetic, please let me know. Or should I just buy the more expensive ones specifically sold on the synthetic urine websites