A hybrid solar heat collector within a translucent dome structure includes a tubular frame, forming a first fluid path, and a transverse hose winding in a spiral inside and outside alternating legs of the frame to form a second fluid path. The first fluid path is connected to a reservoir in which a heater that is turned on to heat a fluid in the first fluid path when its temperature falls below a threshold. The reservoir is located within the dome structure and is configured to readily heat the space within the dome structure, so that the freezing of fluids within the heat collector is prevented. The translucent dome structure is provided with a layer having an opacity that is increased in response to an increase in temperature above a different threshold level, so that the boiling of fluids within the heat collector is prevented.