What can I do for a major sun burn other than aloe?

Cool area. Cool showers, Aspirin or Ibuprofen to reduce inflammation, aloe, drink plenty of fluids and replace electrolytes with a sports drink to avoid getting dehydrated.
Sunburn relief. My favorite secret tips, handed down from my grandmother, include 2 regular Aspirin every 4 hours (not for kids under 12), white vinegar as often as necessary to take the sting out, and sarna or similar no-itch lotion. Don't tell my grandma i told you!