This is a collaborative study performed by three different scientific groups, from Athens (Greece), Baku (Azerbaijan) and Sofia (Bulgaria) concerning the influence that geomagnetic disturbances and cosmic ray activity might have on human physiological and cardio-health state. All the above groups have conducted separate studies, in the past, regarding this subject and the results are irrefutable, the human organism is sensitive to environmental changes and reacts to them through a series of variations of its physiological parameters such as systolic blood pressure, diastolic blood pressure, heart rate, human brain’s bioelectrical activity, etc. This study refers to the time period from 15th July 2005 until 31st March 2008. Daily heart rate data, which were digitally registered for seven functionally healthy persons in working days (including Saturdays) in the Laboratory of Heliobiology, the Medical Centre INAM, Baku are related to daily variations of cosmic ray intensity, as measured by the Neutron Monitor of the University of Athens (http://cosray.phys.uoa.gr) and daily variations of Dst and Ap geomagnetic indices. The time interval from 4 - 22 December 2006 is most interesting as it is characterized by extreme solar and geomagnetic activity. Intense cosmic ray events were recorded during this period, such as a series of Forbush decreases started on 6th December 2006 and lasted until the end of the month and a solar proton event causing a Ground Level Enhancement (GLE) of the cosmic ray intensity on 13th December 2006. A sudden decrease of the cosmic ray intensity on 15th December resulted in a magnetic storm, which was recorded also in Athens station (cut-off rigidity 8.53 GV) with amplitude of 5%. Our study has revealed that during geomagnetically quiet days the heart rate and the cosmic ray intensity variations were positively correlated. When intense cosmic ray variations, like Forbush decreases, occur, cosmic ray intensity and heart rate get minimum values and their variations also coincide. This paper describes a part of the results of a recently established and extended co-operation and a further complex investigation, performed by aforementioned three groups, will hopefully have a lucrative outcome.