I can report the same ....... At first I was sure that heat lowers the Blood Sugar, but I am pretty convinced that, for me at least, the opposite is true. I am having a terrible blip with my control - with similar weird responses to what are very low carb options, like chicken salad ..... 8.2 three hours after eating !!!!!
Very depressed and fed up.
But it looks like I am not alone - and that's why this forum can be very helpful. I bet once the temps come back to normal, we'll see a shift in our sugars - fingers crossed.