If the product meets the criterion for temperature check set in section 7.4.3 of harmonised standard EN IEC 60350-1:2016, then the product should be regarded as complying with the temperature requirement set in Annex II (1), because application of harmonised standards provides presumption of conformity.
However, if there is evidence that the product has been designed so that its “performance is automatically altered in test conditions with the objective of reaching a more favorable level for any of the parameters specified in the relevant delegated act or included in any of the documentation provided with the product” then the product is in breach with article 3(5) of the Energy Labelling Framework Regulation (EU) 2017/1369 and cannot be placed on the market.
Disclaimer: Please note that the European Commission cannot provide a legally binding interpretation of the EU legislation, as this is the sole competence of the European Court of Justice. Any remarks from the European Commission services are without prejudice to the position the Commission might take should related cases arise in a procedure before the Court of Justice.