If one substance floats in another it must be dense

True
Or
False

true

Explanation:

Density is the only thing affecting whether something floats or sinks. If an object has a higher density than the fluid it is in (fluid can mean liquid or gas), it will sink. If it has a lower density, it will float. Density is determined by an object's mass and volume.

your body is trying to warm itself up. or more precisely, sensors in your skin send messages to your brain to generate heat to your body.