A hosepipe ban is on the horizon if hot weather continues, a water firm has warned.
United Utilities has sent an urgent plea to its Lancashire customers asking them to conserve water during the heatwave.
If not, the firm warned, a hosepipe ban could be on the way.
Customers were told "we urgently need your help to avoid a hosepipe ban".
A letter from United Utilities stated: "The hot weather means we're seeing a massive increase in water consumption across our area.
"Yesterday an additional half a billion litres was used.
"We urgently need your help and support to avoid a hosepipe ban.
"You can help us by turning off your garden sprinklers, not using your hosepipes and taking shorter showers and not baths this weekend.
"The demand is so high, particularly during peak times, that we are struggling to get enough water around the system quick enough. If we can all do our bit this will reduce the risk of lower water pressure or no water at all."
A spokesman for United Utilities added that people might see low water pressure as a result of high demand for water. Low water pressure has been reported this morning in Preston, Bolton and Wigan.