The group spotted the animal struggling to escape the icy water near the southwestern city of Parnu when they arrived to carry out dredging work at the Sindu dam.
They cleared a 100-metre path through the ice before pulling it from the water, wrapping it in a towel and driving it to a nearby veterinary clinic.
“He was calm, slept on my legs,” one of the men, Rando Kartsepp, told the Estonian newspaper Postimees. “When I wanted to stretch them, he raised his head for a moment.”
While they and the veterinary staff had suspicions about the true nature of their new friend, the truth was only confirmed when a local hunter saw it at the clinic.
The wolf, believed to be around one-year-old, was treated for severe hypothermia and shock and given parasite control drugs.
He was released into the wild on Thursday with a GPS tracker fitted in a “nice yellow collar”, according to the Terveks Clinic.
The workers appeared unfazed by the discovery, although they doubted they would have managed to handle a full-grown wolf.
“The experience was new. We hope he will be fine,” said Mr Kartsepp.
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