A mobile service block system including prefabricated bathroom, kitchen and other service room units in a single compact and mobile form for installation and use in buildings. In one aspect, an apparatus includes a processor configured to allocate a plurality of resource blocks for wireless communication. A momentary exercise level and the level of fatigue of a person are measured or estimated by measuring besides electrical signals received from muscles also other quantities describing exercise and from measuring results one or several indexes are calculated by means of which exercises carried out at different times and under different circumstances are comparable with each other. Responses including requests for additional information, approvals and denials are provided by the system. The cooler provides the circulating, cooling water used to adjust the temperature of the operating cell and of the electrolyte solution to within a given temperature range in order to ensure that the cell is not affected by excessively elevated temperatures that can stop operations due to cell overheating.