Sleeping problems. Anyone else?

I have a 15 month old son so sleeping is always at a premium. I'm so lucky that my husband takes toddler duty until I get up for the day if he's up early. Last night and other nights I've had a racing heart and cold/hot flashes but no temperature and I don't feel sick otherwise. I couldn't get to sleep until 3am and my husband was up with our boy at 4:30! Anyone else experience this feeling at night? Any good remedies??