It is 5 F outside; however, I have not had any problem with getting desired heat in rooms, until today. We have gas heat in our house. I hear water thru the hot water baseboard heaters in every room. Rooms are not making it to the set temp of 69 F
As fixer1234 suggests, your heating system is probably not designed to heat your house to 64 Fahrenheit degrees above the outdoor air temperature.
You can provide more heat by running incandescent lights in most rooms of your house. You can also find reasons to cook things that do not require running your kitchen exhaust fan more than usual.
To prevent this problem from happening in the future, you can improve the insulation of your house (such as by adding storm windows). If there are any drafty parts of your house, you can seal cracks to minimize the drafts.
For example, Seattle's Energy Code mandates that builders design heating systems that can heat a house by 46 F° above the outside air temperature. A typical house built to the 2006 Seattle Energy Code loses its heat as follows:
- 40% to intended draftiness ("Infiltration" or "Air Changes per Hour")
- 20% via the roof, basement floor, and basement walls
- 20% via doors and windows
- 20% via the remaining above-ground walls