Under Rug Heating?

[MyNescafe]

I made the mistake of having my largish open plan kitchen/diner fitted with ceramic floor tiles without considering under floor heating before hand.
They are cold, even when the weather is warm(ish!)

I would really love to rip the lot up and have proper under floor heating but I just can't justify the cost or upheaval.

I've seen these heat mats that can be used under rugs that look a bit like an electric blanket (RugBuddy is one type). Has anyone any experience of these? Just wondering if they cost a fortune to run and how much heat they really provide?

Appreciate that I can't cover the entire floor with rugs but maybe one or two might help?

heating by electricity costs about three times as much as heating by gas.

To warm your largish room might need 3 or 4 kW of energy.

I doubt a rug mat has more than 300W. I can imagine it might warm your feet while you sit in front of the TV, or make your cat happy. I don't believe you will notice any difference in the room.

Some people might fall over the flex.

Think I may just stick with the fluffy slippers and a disappointed cat then!
Thanks PigletJohn