Code Orange alert for dangerous heat is declared once again for seven Bulgarian regions Monday.

The forecast is issued by the National Institute for Meteorology and Hydrology at the Bulgarian Academy of Sciences, BAS.

Code Orange for heat is effective for the regions of Pleven, Ruse, Veliko Tarnovo, Yambol, Stara Zagora, Haskovo, and Lovech. The mercury in these regions will climb to 38 - 40 degrees Celsius

Code orange means intense weather situations with potential damage, injuries and casualties.

People are advised to not venture outside, especially around noon and during the afternoon; to strictly follow the directions of the authorities and be prepared for emergency measures. Plenty of water is to be drunk.

Only six regions are under Code Green – Sofia City, Sofia, Pernik, Vidin, Montana, and Smolyan, while the rest of Bulgaria (15 regions) is under Code Yellow.

Code Yellow means potentially dangerous weather, where the forecast is not for unusual meteorological events, but requires people to exercise caution.

Temperatures there are to reach anywhere between 34C and 39C with uncomfortable heat and muggy air.

Some rain and thunder are expected in western Bulgaria in the afternoon.

The weather on the Black Sea Coast will be sunny. Temperatures will be between 32C and 34C degrees and 26-28C for the sea water.

According to the weather people such heat wave is not unusual and occurs on average every five years. In Bulgaria, the most recent heat wave was recorded in July 2007 when the mercury reached 45C in some locations.