humidity ???

i have a plant thats been vegging for a few weeks in a green rubbermaid container approx. 15"x24"x15" i have 4 42w cfls in there right now with the top peice slightly cracked open.. how would you guys recommend getting more humidity while keeping the heat below 100 degrees which is what it gets up to when i close the top completely

any important details i left out lemme know, ill be around these forums for a few more hours tonight :rasta: