Ok i have the heater, but I'm afraid to put it in his hospital tank considering it is only a 1/2 gallon. Also the only one they had at the store small enough for a 2 gallon does not have a dial on it. any suggestions on how to acclimate him to the warmer water. I don't think he has ever been in heated water.
Also the blood worms come in cubes about the size of Fritz's body. Do I cut them up or thaw them first?
Thanks again for all your help.
Glad you got the heater so quickly. As I suggested before, I would test it first on a clean bucket/tank of water to make sure it is working well and the gauge on the heater corresponds with the reading on the thermometer. I was also nervous at first too, I also have a 1/2 gal hospital tank which I am currently using, as mine is tall and narrow, I am able to keep the heater in there nicely, and the temp. does not fluctuate whatsoever. If you have a short and wide tank, then you will have to lay it flat.
What is the current temp your betta is in now? If let's say it's 65F, then set the dial on the heater to 67F (after testing) to start, increase the dial by 2 degree every day until you reach about 78-79. May be someone else have better suggestion, but that's how I would do it.
Yes, the blood worms come in cubes

When you take one out, cut them into 6 cubes, and only thaw one and put the rest back in the freezer. Some people use the tank water to thaw it, but I just leave mine out in room temp for a bit and then feed directly. Use tweezers to help you handle them, feed one bloodworm at a time, and about 1-3 depending on their sizes and frequency of feeding. Immediately put the rest back in the fridge, seal well and you can keep them for 2 days or so.
Good luck! I am really hoping that heat with daily water change and food will make him feel better. Let us know if his symptoms and behavior change.
Cheers!