16. (1) Except in cases of special necessity, persons from whom forced or compulsory labour is exacted shall not be transferred to districts where the food and climate differ so considerably from those to which they have been accustomed as to endanger their health. 16. (2) In no case shall the transfer of such workers be permitted unless all measures relating to hygiene and accommodation which are necessary to adapt such workers to the conditions and to safeguard their health can be strictly applied. 16. (3) When such transfer cannot be avoided, measures of gradual habituation to the new conditions of diet and of climate shall be adopted on competent medical advice. 16. (4) In cases where such workers are required to perform regular work to which they are not accustomed, measures shall be taken to ensure their habituation to it, especially as regards progressive training, the hours of work and the provision of rest intervals, and any increase or amelioration of diet which may be necessary. Article 17 17. Before permitting recourse to forced or compulsory labour for works of construction or maintenance which entail the workers remaining at the workplaces for considerable periods, the competent authority shall satisfy itself(1) that all necessary measures are taken to safeguard the health of the workers and to guarantee the necessary medical care, and, in particular, (a) that the workers are medically examined before commencing the work and at fixed intervals during the period of service, (b) that there is an adequate medical staff, provided with the dispensaries, infirmaries, hospitals and equipment necessary to meet all requirements, and (c) that the sanitary conditions of the workplaces, the supply of drinking water, food, fuel, and cooking utensils, and, where necessary, of housing and clothing, are satisfactory; (2) that definite arrangements are made to ensure the subsistence of the families of the workers, in particular by facilitating the remittance, by a safe method, of part of the wages to the family, at the request or with the consent of the workers; (3) that the journeys of the workers to and from the workplaces are made at the expense and under the responsibility of the administration, which shall facilitate such journeys by making the fullest use of all available means of transport;