A game where the two players kiss without stopping and without touching each other. If one player touches the other, s/he loses. The winner gets to do whatever s/he wants to the loser.
On The L Word, Shane and Carmen played a steamy game of Too Hot.
When something has too much attention
We can't gamble in the restroom, it's too hot.
The resulting message concluded when one runs a radioactive sample through a scintillation counter that exceeds its measuring capabilities. A scintillation counter is a device for detecting and assaying scintillations produced by ionizing radiation.
To her delight, Amy discovered that her radioactive samples were TOO HOT to be assayed by a scintillation counter.