WHO has developed standardized health kits of medicines and medical supplies to meet different health needs in humanitarian emergencies and disasters. These kits are developed to provide reliable and affordable medicines and supplies quickly to those in need. The kits are used by United Nations agencies, nongovernmental organizations and national governments. Based primarily on WHO’s Essential Medicines list and guidelines on treatment of specific medical conditions, the contents of the kits are frequently reviewed and updated to adapt to changing needs based on experience in emergency situations. A certain number of kits are prepositioned in strategic locations to be mobilized quickly in times of need. Long term agreements with suppliers are also in place to ensure rapid shipment wherever needed.