DCD chief Dr Jessada Chokdamrongsuk predicted there would be between 150 and 400 heatstroke patients a month this summer – with the number peaking in April and May.

It was predicted that Thailand’s temperature might soar as high as 43 degrees Celsius over the next week.

Heatstroke risks are highest among people who carry out activities under the sun for a long time, such as farmers, soldiers and athletes.

Younger children, the elderly, people with chronic illness such as hypertension and obesity, people suffering sleep deprivation, and heavy drinkers were also at higher risk.

Symptoms include exhaustion, light-headedness, fainting, a high body temperature with a lack of sweat, nausea and vomiting, and a throbbing headache.

Thailand had between 2,500-3,000 cases of heatstroke per year from 2014-2016 with the patients’ average age 41.

According to the DCD, 21 people aged between 29 and 72 died from heatstroke between March 1 and April 17, 2016, and most died in public places.