I've seen several questions asked here, and will try to answer a few.
1. The Earth is heated by solar radiation all across the spectrum. Harmful radiation is mostly blocked by the Earth's magnetic field and it's atmosphere. What comes through provides heat for the planet.
2. Light, microwaves, gamma rays, etc... are massless. A medium is not required for travel, but is required to interact. ie. space cold, Earth warm.
3. Pressure and temperature are relative. Lower pressures at higher altitudes yield lower temps. Ask a scuba diver about gas laws.
4. As stated before. the primary reason for seasons is not distance but the angle of the Earth on its axis. At a steep angle some of the sun's rays skip off of the atmosphere and into space.