NOVELTY - The device has a supply pipe (12) supplying a fluid e.g. water, to be heated, to a thermal solar surface (3) that is provided with a set of thermal solar sensors e.g. glazed sensors, and a sampling pipe (13) sampling the heated fluid by the surface. A movable sunshade (4) i.e. opaque rigid panel, regulates temperature of the fluid. The sunshade is placed in a deployed position in which the sunshade covers a masked part of the surface to avoid direct exposure of the masked part to the sun for reducing overheating of the fluid by the surface.    USE - Device for directly and indirectly heating fluid e.g. coolant such as liquid fluid e.g. water, that is stored in a heating and storage reservoir e.g. bowl, central heating device, cistern, tank, bunker and swimming pool, by thermal solar energy, for producing sanitary hot water and distilled water and for being arranged in a roof, a wall, a flat roof or terrace, and a garden of a building or a dwelling. Can also be used for heating gaseous fluid and aqueous solution comprising water and anti-freeze compound, e.g. methanol and ethylene glycol, and for drying a cereal.    ADVANTAGE - The movable sunshade permits to regulate the temperature of the fluid without thermostatic faucet mixing valve, thus conserving integrity of the solar sensors irrespective of utilized thermal solar sensors during intense insulation period in which the device is not activated, and hence avoiding risk of thermal impacts. The device therefore increases life duration of the sensors. The sunshade is placed in the deployed position in which the sunshade covers the masked part of the surface to avoid direct exposure of the masked part to sun for reducing overheating of the fluid by the surface, thus avoiding excessive overheating of the sensors, and hence avoiding over dimension of the sensors. The device can be operated and regulated in an automatic manner, and can be manually handled in a simple manner. The configuration of the device permits to ensure favorable energetic balance and to protect the sensors against snow, hail and rain.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a heating device for indirectly heating a fluid by thermal solar energy.    Thermal solar surface (3)    Movable sunshade (4)    Supply pipe (12)    Sampling pipe (13)    Sensors (32, 33)