? Heat and raised BG?

Hi all,
It's been a while since I've posted, but wanted to get some thoughts. Nico had a recent UTI, but two pee tests later I think we're all good. D-mannose and corn silk have helped him out tremendously.
I thought we had got his BG back under control after the UTI, but I noticed he had some low spots and obvious swings. Nothing major just enough to notice I had to lower his dosage a bit.
Now comes the most recent heat wave. It's been consistently in the 80's the past two weeks, and we don't have AC. The past two days especially the house has not cooled down, and it seems as though Nico's BG is higher due to the heat.
Has anyone experienced fluctuations in BG with heat? I keep putting ice cubes in the little guys water fountain, just trying to help him stay cool. I'm thinking it may be time to put the window units in to help him out.