Heat wave will prevail in UP in the coming five days.  The Meteorological Department has issued an alert of hot night for some districts.Most of the country is in the grip of extreme heat.  Heat wave is going on in UP.   The Meteorological Department has issued a warning of heat wave lasting two to five days in many states including Uttar Pradesh and Bihar.  Red alert has been issued for heat wave in West Bengal and Odisha.  On the other hand, there was rain and hailstorm with strong winds in Punjab on Saturday. The Meteorological Department has advised pregnant women and children not to go out of the house.  On the other hand, Friday was the hottest day of the season (40 degrees Celsius) in the national capital Delhi.  Senior meteorologist Atul Kumar Singh said that the maximum night temperature is likely to increase by four to five degrees Celsius in many areas of the state for the next two days.  It is called hot night or warm night.