Wildfires ripped through forests amid the scorching heat in Thailand.

The flames erupted in the hillsides of Phayao province in the north of the country, triggering 'hot spots' in 37 areas.

Aerial footage shows the blaze eating through the woodlands, causing thick smoke to spread to surrounding areas, including the Phayao University, on March 12.

Authorities said the Wiang Lo Wildlife Sanctuary suffered the worst of the inferno.

Firefighting teams have been mobilised to contain the fires.

The Thai Meteorological Department warned of 'hot to very hot' weather with maximum temperatures of 40 degrees Celsius in northern Thailand on Wednesday.

The wildfires also come during the yearly agricultural burning season in the country, when selfish Thai farmers set fire to crops to cheaply clear their land.

Scientists found that smog is at its worst in the country during crop burning season in late October and April. The agricultural process known as 'slash and burn' is quicker and easier than crop rotation fields and leaves a nutrient-rich layer of ash that helps to fertilise new crops.

However, the side-effect is severe air pollution full of toxic PM2.5 particles that cause respiratory ailments. The pollution has also worsened in recent years due to the rising demand for food from rapidly developing cities in Southeast Asia.

The lack of wind and rain during the same period, combined with a winter low-pressure system in which cold air is trapped closer to the ground by warm air above, prevent the smog from being dispersed naturally by wind.

Thailand's government has been criticised for failing to tackle the country's air pollution crisis, with bizarre measures such as spraying water into the air, placing giant purifiers on roads and even using cloud-seeding planes to cause downpours. There have also been claims that they are under pressure from powerful food conglomerates to allow the intensive farming methods.

Data scientist engineer Worasom Kundhikanjana said that the pollution will return annually without draconian policies banning agricultural burning.

She said: 'PM 2.5 pollution has a seasonal trend in Bangkok and the northern provinces, but has only recently received public attention. During this winter haze, the harmful particle pollution level is high throughout the day, including on weekends.

'Unfortunately, spraying water into the air does not appear to be effective, since the volume of water is minuscule compared to actual rain.

'With the start of the monsoon season, the weather in Bangkok will get better, and public attention on this issue will likely fade. However, without immediate policy measures, the problem will come back again next winter.'