The vegetation constitutes a crucial element, which influences on several levels such as the aspect the esthetics and the attractiveness of the spaces, the indoor and outdoor thermal comfort as well as the psychological aspect of users. Green spaces are considered places of relaxation and leisure, which represent the lungs of the city by creating a microclimate suitable for users. The dominance of concrete in the city has caused problems through the significant reduction of the surface of green spaces, which directly influences the outdoor thermal and psychological behavior of persons. The objective of this research is to study the influence of green spaces on the outdoor thermal and psychological comfort of users during the hottest period in Biskra city (Algeria). The investigation was based on an empirical approach, a quantitative method by taking measurements with a "Testo 865" thermal camera as well as a qualitative study by observation and interview with users using human biometeorological indices such as the Physiologically Equivalent Temperature "PET", the Thermal Perception "TP" and the Physiological Stress "PS". The results confirm the importance of urban green spaces and their positive impact on the assurance of outdoor thermal comfort, and the good behavior of users and demonstrate the major role of vegetation despite the difficult climatic conditions of the city of Biskra. For this purpose, the use of trees is recommended, in particular the "Ficus" type, because of its proven physical and psychological benefits for people.

The vegetation constitutes a crucial element, which influences on several levels such as the aspect the esthetics and the attractiveness of the spaces, the indoor and outdoor thermal comfort as well as the psychological aspect of users. Green spaces are considered places of relaxation and leisure, which represent the lungs of the city by creating a microclimate suitable for users. The dominance of concrete in the city has caused problems through the significant reduction of the surface of green spaces, which directly influences the outdoor thermal and psychological behavior of persons. The objective of this research is to study the influence of green spaces on the outdoor thermal and psychological comfort of users during the hottest period in Biskra city (Algeria). The investigation was based on an empirical approach, a quantitative method by taking measurements with a "Testo 865" thermal camera as well as a qualitative study by observation and interview with users using human biometeorological indices such as the Physiologically Equivalent Temperature "PET", the Thermal Perception "TP" and the Physiological Stress "PS". The results confirm the importance of urban green spaces and their positive impact on the assurance of outdoor thermal comfort, and the good behavior of users and demonstrate the major role of vegetation despite the difficult climatic conditions of the city of Biskra. For this purpose, the use of trees is recommended, in particular the "Ficus" type, because of its proven physical and psychological benefits for people.