The present document describes the thermal management requirements for outdoor enclosures defined in EN 301 169-1 [i.4] and EN 301 169-2 [i.5]. These thermal management requirements to be defined include: ? a standardized definition of cooling capacity for outdoor enclosures; ? a maximum acceptable delta T between ambient temperature and inside temperature; ?the preferable rule for air flow inside outdoor enclosures; ? the environment class for equipment to be installed in outdoor enclosures. Not all these requirement are applicable to outdoor enclosures defined in EN 301 169-1 [i.4] and EN 301 169-2 [i.5]; maximum acceptable delta T for equipment in line with EN 301 169-1 [i.4] should be considered as a guide to developer. The purpose of the present document is to make it more easy to define the responsibility of equipment manufacturers@ cabinet manufacturers and integrators. The present document applies for those empty outdoor enclosures supplied for housing telecommunication equipment of wireline and wireless access network and other information technology equipment. EMC@ safety and acoustic noise requirements are not parts of this document. Guidance on these aspects are contained in annex D.