Boiler broke, child at home.

Our boiler broke this morning, repair guy won't be out until tomorrow. The house is currently 12 degrees Celsius. My daughter is 16 months. Is it safe for her to sleep here tonight? She is in fleece pajamas and a sleep bag. I have an electric heater on in her room at the moment but don't think it's safe to leave on over night. Never had a situation like this before.