Garner-Gatley said she had started going to bed earlier to keep warm while watching television and had recently begun using a hot water bottle and bed socks as evening temperatures dropped.
She said instead of keeping hot water on a timer, she only switched it on when she needed it for washing, cooking or bathing before turning it off again.
She added that people living in rural areas who depended on oil had “no choice” but to buy it.
She said: “After working all my life I didn’t expect to be constantly worrying about how to keep warm at my age. It is really quite frightening.”
Heating fuel costs have risen by up to 82% since the start of the US-Israeli war with Iran, according to Minster for Energy Consumers Polly Billington.
Earlier in October, the government promised better regulation of the sector.
Ministers said they would tighten up rules, promote competition and give customers clearer compensation routes if things went wrong.
Minimum order levels set for some customers would also be reviewed, they added.
Cornwall Council and Devon County Council have money available for households struggling with increasing heating oil costs from their crisis resilience funds, which are provided by the government.
Cornwall Council said it had issued payments of £300 to £1,386 households, a total spend of £415,800, which would double after a decision was made to award a further £300 to the same households.
The Devon fund, worth about £8.4m a year, is available through district councils, and is targeted at low‑income households facing an “essential cost they cannot afford”.
Plymouth City Council and Torbay Council also have their own crisis resilience funds.
