Refer to figure.
Vectoring. Provision of navigational guidance to aircraft in the form of specific headings, based on the use of an ATS surveillance system.

ICAO Doc 4444 - Air Traffic Management
8.6.5 Vectoring

8.6.5.1 Vectoring shall be achieved by issuing to the pilot specific headings which will enable the aircraft to maintain the desired track. When vectoring an aircraft, a controller shall comply with the following:

a) whenever practicable, the aircraft shall be vectored along tracks on which the pilot can monitor the aircraft position with reference to pilot-interpreted navigation aids (this will minimize the amount of navigational assistance required and alleviate the consequences resulting from an ATS surveillance system failure);

(...)

ICAO Doc 8168 - Volume III
Chapter 4 - ALTIMETER CORRECTIONS

Note: This chapter deals with altimeter corrections for pressure, temperature and, where appropriate, wind and terrain effects. The pilot is responsible for these corrections, except when under vectoring. In that case, the controller issues clearances such that the prescribed obstacle clearance will exist at all times, taking the cold temperature correction into account.

When an aircraft is being radar vectored, ATC provides headings to fly and altitudes to reach or maintain. According to ICAO Doc 4444 when an aircraft is being vectored, the pilot should whenever practicable be within the coverage of any navigation aid to cross-check the aircraft position. Based on ICAO Doc 8168 (Volume III), when under vectoring the controller should issue clearances taking the cold temperature correction into account.