A dual dosimeter system with (1) a stick-on, self-indicating, instant radiation dosimeter applied onto (2) a conventional radiation dosimeter and/or detector for monitoring high energy radiations, such as X-ray, electrons and neutrons. Radiation dosimeters, such as X-ray film and TLD (Thermoluminescence Dosimeters), are highly sensitive but are not instant. Radiation detectors, such Geiger counter, ionization chamber and silicon diode type electronic detectors, are highly sensitive and instant but have several other drawbacks, e.g., they are fragile, bulky, dose rate dependent or require electrical power. In the event of a dirty bomb, nuclear detonation or a radiological accident, one needs to know the harmful high dose (e.g., higher than 0.1 rad) instantly so proper precautions can be taken and medical treatment, if required, can be given to the victim. If a self-indicating instant dosimeter is applied to the conventional dosimeters and detectors, one would know high dose instantly.