I'm actually looking for 2 chemicals that will produce a really small exothermic reaction. The 3rd chemical would be there to separate the chemicals - like oil, water, and air.
Ideally, the 3rd chemical would be a nonreactive oxide of the other 2.
Also, they should all stay liquid on a hot summer's day.
As stated, they should produce a small exothermic reaction - I'm looking for mostly light that won't melt a glass bottle. Melting the bottle isn't ideal, but I can find a stronger material too.
Also, the chemicals should be as nontoxic as possible. They don't have to be though.