A 42-year-old man died of suspected sunstroke in Kallara, Kottayam district on Friday, police said.
Sabu from Mundar in Kaduthuruthy was fishing in a stream when he suddenly collapsed and died on the spot aroundnoon, they said.
His body had burn marks indicating he suffered heat stroke, police said, adding the exact cause of the death could be ascertained only after postmortem.
Many parts of Kerala are reeling under heat wave conditions with soaring mercury levels in the past several days.
For the third consecutive day yesterday, Malampuzha in Palakaad district recorded the highest temperature of 41.7 degrees Celsius in the state.
Seventy cases of sun burn and one death had so far been reported from the district even as Kerala has approached the Centre to declare the state as 'drought hit'.
The government has also decided to give Rs four lakh assistance to the next of kin of those who had died due to the sizzling heat.
There was crop loss in about 1,038 hectares due to drought and the government will provide compensation to the farmers.
Malampuzha recorded 41.9 degrees Celsius, the highest in 29 years, on April 26.