when i installed my trust worthy heater, it failed me. the temp rose over 100 degrees and almost cooked my fis. i noticed him acting strange and when i put my thermometer in.. KABOOOOM! the temp shot up sooo high.
i am shocked that my heater broke.
OMG that's terrible! If I were you I'd transfer your fish to cooler water right away!
have you ever moved your hand from a bucket of hot water into a bucket of cold water? it doesnt feel so nice. now imagine being fully immersed in a pool of hot water then suddenly thrown into a pool of cold water. if your tank is over heating like that, cup the betta and let his sit out in the cup until it cools to the approximate temperature of the tank you are moving him to, then do the full acclimation. if you just plop him in a cooler tank he will go into shock.