Thanks for your query to us.
Shivering indicates that the body wants to increase it's core temperature. It may be either under the influence of pyrogens (chemical liberated by infections/inflamation which act on brain to increase temperature) or there is a mismatch between the core temperature in brain & actual body temperature. Since infection is one of the possibilities and your father has COPD
(which predisposes to lung infections), i would like you to see your GP and get him assessed. In old patients we can not rely on fever
as a marker of infection albeit increase in cough
/sputum in COPD indicate infective exacerbations.
Hope it helps.