The Pakistan Meteorological Department (PMD) on Saturday predicted that the prevailing heatwave in the country was likely to continue over the next week as well.
Slight relief was expected in most parts of the country from May 14 to 17 because of dust storms, gusty winds, and rain, accompanied by thunderstorms, in scattered places, the PMD said in a statement.
However, day temperatures would again rise from May 18, it stated.
The prevailing hot and dry weather could cause stress on water reservoirs, crops, vegetables and orchards, the PMD cautioned, and advised farmers to manage their crops accordingly.
The rise in temperature could also increase energy and water demands, which was why the latter should be used judiciously, the department said.
Minister for Climate Change Sherry Rehman advised citizens to take greater care in order to avoid heatstroke and heat exhaustion.
In a series of tweets, she noted that senior citizens and children were at high risk.
"Predictions for increased base flow in the rivers during the next week may help. Until then, people are advised to avoid unnecessary exposure to direct sunlight and take precautionary measures. Furthermore, water should be used sparingly. Pets and livestock need protection too."
The minister shared a list of symptoms related to heat sickness, including raised body temperature, exhaustion, headaches, nausea, vomiting and poor coordination and called on district administrations to make contingency arrangements.
Meanwhile, the PMD's Early Warning Centre for Heatwave in Karachi had predicted that maximum temperatures in most parts of Sindh, including Dadu, Sukkur, Larkana, Jacobabad, Shikarpur, Khairpur, Qambar Shahdadkot and Nawabshah, would remain between 48 degrees celsius and 50°C today.
Meanwhile, the maximum temperature in Hyderabad, Badin, Mirpurkhas, Umerkot and Tharparkar would range from 44°C to 46°C.
The heatwave would ease slightly between May 14 and 17 with a 3 to 4°C drop in temperatures but would intensify again afterwards.
Swathes of the country have been smothered by high temperatures since late April, in what the World Meteorological Organisation (WMO) has warned is consistent with climate change.
"This year we have jumped from winter right into summer," said PMD chief forecaster Zaheer Ahmad Babar.
Pakistan has endured heightened heat waves since 2015, he said, focused in upper Sindh province and southern Punjab province.
"The intensity is increasing, and the duration is increasing, and the frequency is increasing," he told AFP.
The Punjab and Sindh governments have already directed departments to stay alert, asking them to take measures to minimise the impact of the hot spell.
Additional reporting by Qazi Hassan from Karachi.