I have to write an article about geothermal energy, and I have two ideas for the headline:
- Geothermal energy: A hot way to cool down
- Geothermal energy: A cool way to heat up

The thing is, geothermal energy does both cool down homes and heat them up, so I feel like I'm only saying half the truth in the headline when I use either.
Other ideas?
Maybe:
- Geothermal energy: the source from the soil
- Geothermal energy: the science below the earth

Any other ideas would be appreciated, with puns would be awesome, thanks!