Heat wave killed over 3,600 people across the country in the last five years, the government informed Parliament on Thursday.

Replying to a question in the Lok Sabha, the junior minister for home affairs Nityanand Rai presented the figures of the last four years and the current one, and said the number has been on the decline.

According to the data given, a total of 3,654 people died of heat wave related illnesses during 2015-2019, with 2,040 dying in 2015. The deaths came down to 1,111 in 2016 and to 384 in 2017.

The lowest number recorded was in 2018, when 25 people perished in the heat wave. A total of 94 people are believed to have died this year so far, according to government data.

The minister said the data was not maintained according to the socio-economic status of the dead and that it could not be told whether people dying due to the heatwave belonged to the poor class or rich class.

The data, the minister said, was provided by the Integrated Disease Surveillance Programme in the ministry of health and family welfare.

The indicators that meteorologists set for heat waves vary according to the time of the year and the place. For example if in Delhi, for several days the maximum temperature is 5 degrees above normal and has touched 40 degree Celsius in June, Met officials would categorise that as a heat wave.