There are many causes of back pain.If it has occurred as a result of a strain through lifting etc then taking Ibuprofen for a few days may ease it.
If the pain continues for more than a week and doesn't appear to be easing then contact your GP for further investigation, as other injuries/disorders can manifest as back pain eg kidney infections and gallstones
Sorry to hear you have a bad back bobo, if you can afford it try an osteopath. Mine costs about �25 a time, and you may need more than one go, but I think it's worth it. I felt a big improvement even after 1 go. PS Don't forget to wear clean undies - if you can get em on!
Although applying heat can be comforting, it isn't necessarily the right thing to do. When I hurt my back last year, I started using those bands that heat themselves up. It gave lovely support and felt wonderful but after a couple of days, It wasn't getting any better so I went to an osteopath. I had inflammation and heat was the wrong thing, I should have been applying ice packs. Best thing is to get professional advice.