Method of cooling a wind turbine

A method of cooling a wind turbine, the method comprising:

• operating a cooling system with a first setpoint temperature to cool the wind turbine over a first period;
• measuring a temperature of the wind turbine over the first period to obtain temperature measurements;
• allocating each of the temperature measurements to a temperature range, wherein one or more of the temperature ranges are critical temperature ranges;
• for each critical temperature range, comparing a parameter indicative of a number of the temperature measurements allocated to the critical temperature range with a threshold;
• selecting a second setpoint temperature on the basis of the comparison(s);
• and
• operating the cooling system with the second setpoint temperature over a second period,
• wherein if the parameter is less than the threshold for each critical temperature range, then the second setpoint temperature is selected to be higher than the first setpoint temperature;
• and if the parameter is higher than the threshold for at least one critical temperature range, then the second setpoint temperature is selected to be lower than the first setpoint temperature.