Start with "It's so hot outside" then add something that's happened! 

Remember to keep it HP-appropriate. 

It's so hot outside all of the vehicles' tyres have stuck to the roads!

It's so hot outside i can cook an egg without a frying pan

I used to think the worst thing in life was to end up all alone. It's not. The worst thing in life is to end up with people who make you feel all alone. Robin Williams

It's so hot outside cows are producing warm milk!

It's so hot outside the ocean is drying up. 

It's so hot outside, it's Australia! 

It's so hot outside the bees have stopped pollinating!

It's so hot outside I'm sitting in the freezer!

It's so hot outside the birds are flying into things!

It's so hot outside the FLOOR IS LAVA!

It's so hot outside my sunglasses have melted to a crisp! 

It's so hot outside I saw a chicken lay an omelet!

It's so hot outside the window glass has shattered! 

It's so hot outside I used up all the cold water in the shower!

It's so hot outside I ate all the watermelon! 

It's so hot outside, it's like Stacy's Mom.

its so hot outside that everything looks flat

Is so hot outside that we had 4 forest fires start the same week

its so hot outside even the dog doesn't want to go out

It's so hot outside I don't want to get out of bed

It's so hot outside i want to eat watermelon

It's so hot outside there is no snow.