Electric Blankets and Mattress Pads with Adjustable Beds
UL (the safety agency Underwriters Laboratories) advises people NOT to use electric bedding on adjustable, hospital type beds for two reasons.
The first is that controller wires could get caught in the bed raising mechanisms and be pinched or frayed which could lead to electrical shock or a ruined product.
The second reason is that the heating wires inside the electric blanket (or more so in an electric mattress pad) could become lodged in the crevice or crease created at the pivot point of the mattress. This would lead to overheating problems for certain and the possibility of scorching ruining the heated bedding and possibly even the mattress itself. There would be far less danger of this entrapment with a heated blanket but even then you should be careful of this.
So you will have to make the decision whether or not either of these concerns are valid in your particular case.