Octane and Temperature

Can someone brief me about the impact of octane/timing on water temperature. After reading through some exchanges here, I went to a gas station nearby that sells racing gas (100 octanes). I filled up my toy with a 50/50 mix 100/93 octanes to get a 96-97 mix.
Since that time I run hot. I am not sure it is related since the weather has been pretty hot down there in South Florida.
Does anyone have experience in the field?