Doctors' leave has been cancelled in India to help cope with the sick after a heatwave killed at least 1,371 people this week as temperatures soar above 47C (117F).

May and June are India's hottest months, with temperatures regularly pushing above 40C, but meteorologists say the number of days when temperatures approach 45C has increased in the past 15 years.

The death toll in the worst affected states of Andhra Pradesh in the southeast and nearby Telangana is more than double the toll from a shorter hot spell there last year, officials said, with most of those killed elderly or labourers suffering sunstroke or dehydration.

The toll in Andhra Pradesh alone has reached 1,020, officials said, and deaths have been reported in at least four Indian states.

Authorities have cancelled doctors' leave and advised people not to head outside in the middle of the day to avoid the worst of the heat. However for many Indians, staying indoors is not an option.