West Yorkshire Fire and Rescue Service watch commander Chris Bell said the creams used to treat skin conditions were safe to apply but warned they could become flammable when they soak into fabrics, clothes and bandages and come into contact with cigarettes or naked flames.
The creams are used to treat skin conditions such as eczema and psoriasis.
"Hundreds of thousands of people use them, we're not sure how many fire deaths might have occurred but it could be into the hundreds," he told BBC 5 Live.
"People are using paraffin-based skin products to treat eczema and psoriasis and various other skin creams, putting it all over their bodies and different parts of themselves - treating themselves for those different skin conditions.
"But unfortunately, that cream can get into fabrics, clothing, bandages and dressings, and become flammable.
"The creams are safe to use in their own right, but if that person is exposed to a naked flame or some other heat source, they can go up."
The comments come after an investigation by the radio station and Inside Out Yorkshire and Lincolnshire found just seven of 38 paraffin-based products licensed in the UK had warnings on their packaging.
Users should not smoke, use naked flames or go near anything which may cause a fire while the creams are in contact with dressings or clothing, according to the Medicines and Healthcare Products Regulatory Agency.
Its advice says "patients' clothing and bedding should be changed regularly - preferably daily - because emollients soak into fabric and can become a fire hazard".