Blankets fail the 'safe and sound' tests.
As part of annual "Safe and Sound" roadshows held in Barry and Penarth, pensioners were offered the opportunity to have their electric blankets tested by experts.
More than 60 per cent of 64 blankets failed the tests and were replaced free of charge.
Many were worn out or had poor wiring, broken controls or no protection against overheating.
Trading standards offer the following advice:
Read the instructions carefully and use the blanket correctly.
Keep the instructions with the blanket and refresh your knowledge every year.
Check the blanket is not soiled, scorched or wet, or that any wires are loose or in bad condition.
Store in the recommended way.
Do not position electric underblankets on top of the bed covers (that is, above the person sleeping in the bed), and
throw out electric blankets that are more than 10 years old.
Kate Palmer, the Vale council's trading standards consumer education officer, said: "These results show how important it is to have electric blankets checked regularly."
SAFETY officers in Rhondda Cynon Taf will test electric blankets as the night temperature plummets.
They will carry out free checks on blankets owned by people over 60 at St Mair's Day Centre, Aberdare, on October 31 from 9.30am.