Any tips for kids sleeping in same room?

Summer is nearly upon us. That means highs in the mid-90s and rooms that don't cool off much at night... and Matthew's been waking up sweating and crying in the middle of the night, even w/fan on. So, we moved Matthew's bed in to Hannah's room where there's air conditioning. So far it's been hard to get them to sleep in a timely manner (Hannah came into my room an hour after bed time last night, holding Matthew's diaper. Hmmmm.) And they've been up at least 45 mins. earlier than normal (in the 5:00am hour), too.

Glad for your input,
Lisa