Bermuda grass is a warm season grass and should be ok in the heat you’re experiencing…have you checked the setting for that zone to make sure it’s set to warm season grass?
Here is the irrigation tip out of the Lawn Care Nut warm season grass guide:
“Bermuda is a middle of the road water drinker. 1 inch of water a week is going to be fine for most areas outside of the very heat of summer. In July and August if you are not getting rain help where you live, your Bermuda will likely need 1.5” per week. Just be sure to keep each irrigation cycle at ½” of water and separate your waterings by 2 - 3 days or so.”
Unfortunately you will have to wait until late spring to reseed your Bermuda lawn. Until then I would suggest getting a soil sample test so you can get an idea what issues you may have with your soil. Also, take one of your longest screwdrivers and see how far you can push it by hand into the ground, if you can’t push it more than a couple inches you may have a really compacted soil. If it compacted, your grass is going to have a really hard time growing the deep roots that it needs to survive a hot summer. Compacted soil can be helped with either core aeration or there are liquid methods that you can spray from a hose end sprayer. If you get some of these things started now, by the time you reseed in late spring, your soil will be better prepared and you should get a much better result!