I don't mean does the source of light produce heat (as in the sun, light bulb fire, etc) but does the light itself contain heat. For example if you were to travel at the speed of light, in a beam of light would it be warmer in the light or outside of it?
Heat is the manifestation of vibrating molecules, atoms, or both. As light has neither, no it does not contain heat. Of course it can and does create heat. When radiant energy, photonic energy, strikes matter and gets absorbed, that results in the molecules, atoms, or both of the matter vibrating more vigorously. And that means more heat in the struck matter.
No heat in light. But heat radiation (infrared radiation) often accompanies visible light, as it is just longer in wavelength than visible red colour, e.g. you feel heat in the sunlight, or from a glowing heating element.
Actually no. Light is an energy that does not have any mass, which is why light can travel as quick as it does. Light, such as from a powerful light source as a worklight, or sports arena lights, create heat via radiation. The heat generated by the lamps themselves is being transferred via radiation, and not being carried by the light energy itself. But the radiation faces less resistance travelling with the light. (Simple example: you are more likely to be heated by an open fireplace than you are by a closed wood stove flame.) As it seems though, radiation and light both travel together- but they are different energies. The light is being created by the filament in the bulb, which comes from the heat in the filament. But the heat from the filament cools down as it goes along space- even travelling ambient through radiation. To test this, turn on a worklight and let it run for 10 minutes. Then turn it off, bring it outside. Turn it on again, and point it somewhere- stand in front of it. You should feel the heat. But now, walk back twenty paces. Do you feel the same heat?
