As summer rolls around again, Karachi is set to experience yet another heatwave this year, according to the Pakistan Meteorological Department. Here's a brief look back at what happened, and what you need to know to be prepared.

A combination of high temperatures and high relative humidity changes how the body removes excess heat, making it more difficult for the body to cool down, leading to symptoms of heatstroke like nausea and dizziness.

Making some small changes and taking precautions like avoiding heavy meals and strenuous activity during the hottest hours can help the body to better handle the high temperatures.

According to the Provincial Disaster Management Authority (PDMA), those living in urban areas are more prone being affected by the heatwave as urban centres tend to become heat islands. Last year, 65,000 people were treated at 50 rehabilitating centres in Karachi's most affected ─ and densely populated ─ areas.

Pakistan's deadliest heatwave hit last year with 1,242 deaths and 36,000 affected, mostly in Sindh, and temperatures reaching 49 degrees Celsius. The elderly and the homeless were the most affected, while 60 per cent died at home.

The data is provided by LEAD Pakistan, a part of the core group at the Ministry of Climate Change.