Plans to heat a swimming pool with warmth generated by a nearby crematorium have sparked criticisms.
Redditch Borough Council says the move could save £14,000 a year at Abbey Stadium pool.
The Conservative run local authority says the plans would be beneficial to the environment, reducing carbon emissions from energy that would otherwise be pumped into the atmosphere.
But union Unison officials have branded the plans “sick and an insult to local residents”.
Roger McKenzie, Unison’s West Midlands regional secretary, said: “It goes to show yet again that the Conservatives know the price of everything and the value of nothing.”
He added: “Unfortunately, local authorities are increasingly pursuing desperate policies in a reaction to the unprecedented spending cuts imposed from Whitehall.”
The local authority will consult with religious groups, funeral directors and members of the public later this week.