Help please, before I spend £30 pound on heat pads

In our shopping centre there has been a stall that are selling heat pads that worked when you push what looks like a coin that heats the gel up.  Works about a 1000 times.  I would like to get one to put around my back but are not sure if they are just another gimmick.  I have also been looking in our local range shop that is doing a massage chair for £29.
 
Your advice please

hot water bottle

Was doing the exact thing last night  S777.  And it only cost me a £1 from the pound shop

Get a wheat bag or ice/heat pack from Superdrug or Boots. Costs a fiver. Stick it in the freezer for a few hours or in boiling water for 7 minutes i think.

Much bigger than those heat pads if i'm thinking of the same thing.

i was at the physo a few months back and he told me to stay away from these heat pads ,he advised me just to do what s777 said above

u should have asked them do u want to bend over for them as well ,£30 for a heat pad lol