This product can at times involve substantial risk of injury, customers assumes all responsibility for his/her use. Products may contain some ingredients/ materials that could be harmful for sensitive skin. Use with caution and at your expense. If you have a history of skin allergies, it is best to refrain from using the product. If irritation occurs, discontinue use and consult a skin specialist/physician immediately. If you feel back pain for long periods of time while using the product discontinue use and consult a doctor immediately. We do not recommend sleeping in this product under no circumstances.