You can run on lava directly but you’ll take a lot of damage. 1250 damage if you run as fast as possible. To avoid fire damage, you can use fireproof potions (buy from Emporium) or any damage protection item that can help.
If you have a surplus of healing items or consumables, you can simply take the fire damage and heal afterwards.
How to avoid fire damage from the walls
The fire bursting from the dungeon walls can add up quickly to all the damage taken. To avoid fire damage coming from the wall, simply watch out where you’re stepping. There is a pressure plate on the floor that activates the fire trap, go around it instead. You can notice it easily if you look at the floor tiles in the hallways.
How to avoid fire from the floor
If there’s a grill in the floor, there’s a high chance that fire will burst out of it. This isn’t triggered by your action (like the fire in the wall), but instead it bursts periodically, so just wait until the fire runs out or go around it if you have enough room. But be careful, sometimes when you try to go around it, you may walk on an adjoining grill that’s going to burst in flames. Stop for a bit to see the fire patterns before rushing in.