I have a house with radiant heat in the ceiling upstairs and in the floor downstairs. If you put in a small ceiling fan in the upstairs rooms, even if you run it at the lowest speed, you will be amazed at how much warmer the room gets. It pushes all that warm air from the ceiling down to the lower part of the room. You could even use a fan on the floor and have it blowing up to circulate the air in the room.
One advantage of this type of heating system is that it heats the house itself. In a winter power outage I find that it takes over 12 hours before I notice the house cooling down. Once I got home from a business trip at 8am and didn’t realize the power was out until it started to get dark. The house stayed that warm!
An engineer friend of mine told me not to use setback thermostats with radiant heat. The whole house, he says, acts as a heat-sink and it if it cools down it actually takes more energy to heat it back up than it does to keep it a constant temperature.