The UN's World Meteorological Organization (WMO) said that the first week of July was the hottest week on record for the planet as a whole.
According to data from the WMO, last Thursday saw the daily global average peak at 17.08 Celsius.
In a statement, WMO said: "The world just had the hottest week on record," noting that temperatures were breaking records on land and in the oceans, with potentially devastating impacts on ecosystems and the environment."
The current episode is likely to continue with "at least moderate intensity", WMO noted.
The increase in heat-related deaths was higher among older people, women, and in Mediterranean countries, the un agency reported.
However, the data also indicated that measures taken in France since a deadly heatwave two decades ago may have helped prevent deaths there last year.
Meanwhile, southern Iraq's fabled marshland was having its worst heatwave in the past 40 years, the UN’s Food and Agriculture Organization said on Monday, warning of a "devastating impact" on the ecosystem as well as farmers and fisheries.