Ziraki Adjustable Lumbar Lower Back Support Massage Brace

Ziraki Adjustable Lumbar Lower Back Support Brace ok let me start to tell you the i love this brace everyday i suffer from back paint and this is helping me a lot i always use to buy heating pads ,but this works like magic i understand the it can be a little be hot ,but i put the brace and like in 5 minutes i start to fell the healing hot ,and when i feel to hot i just take'm of and i still feeling the heat after for a several minutes, i works with your body heats, i am just wondering if this brace can do any harm to my kidneys i receive this for free in exchange for my honest and unbiased review

https://www.amazon.com/Adjustable-Support-Self-heating-Magnetic-Approved/dp/B014EEYQKM/ref=cm_aya_orig_subj