English 
Can I clean the mattress?
Yes, the waterbed is very hygienic. Unlike a normal bed, the water bed does not accumulate dust and skin debris inside the mattress. Almost all waterbeds have a removable, washable bed that virtually removes dust when cleaned.
Do you need electric blankets on the water bed?
No need. Almost all water bed temperatures are adjusted to your skin temperature by specially designed heaters. It has a thermostat that lets you control the temperature setting. Temperature control is a great pleasure in sleeping on a water bed - never too hot or too cold.
How are the heaters heated? Are they safe?
The heating system is mounted between the mattress and the liner. The variable thermostat keeps the water temperature at your preset temperature while controlling the state of the pad switch.
Yes, they are safe. They are double insulated and are specially designed for heating waterbeds. Since they are all electrical, they must be followed by the manufacturer's instructions for use.
Need to unplug the heater in the summer?
No, even on a hot summer day, your average room temperature will be lower than your normal skin temperature. Just plug the heater into the power supply - the difference is that the heater will run in the summer for less than the winter.