Extreme or high fire warnings have been issued for swathes of Scotland as forecasters predict a scorching Easter weekend.

In a joint message, Scottish Natural Heritage (SNH), Loch Lomond and The Trossachs National Park and Cairngorms National Park all urged anyone heading outdoors to take extra care with camping stoves, cigarettes and throw-away barbecues.

The weather is expected to become particularly warm on Easter Saturday – though forecasters warn a “pollen bomb” will hit those who suffer from allergies – and thousands are expected to head for the country.

Graham Sullivan, SNH uplands advisor, said: “The forecast looks promising for a warm, dry Easter weekend which is great news for encouraging more people to get out and about in our stunning parks and nature reserves.

“We want people to enjoy their visits but it’s important to bear in mind that fires can spread quickly in these conditions and do lasting damage to nature and wildlife.

“When there is a high fire risk, the Scottish Outdoor Access Code advises people not to light open fires and to use a camping stove instead. We would urge people to be particularly cautious when disposing of cigarettes – even a cigarette butt or the smallest of embers left from a campfire can easily start a

wildfire.

“One of the biggest risks is disposable barbecues. These should be taken away and disposed of safely. You may think the barbecue is no longer a risk, but the lingering heat could cause vegetation to smoulder and catch fire.

“A few simple tips can make all the difference in making sure as many people as possible can enjoy our countryside safely.”

The UK suffered one of its hottest summers on record last year, with devastating wildfires blighting the moors around Manchester. This week, firefighters tackled upland blazes in Sutherland and Caithness. Earlier this month there was a wildfire on Harris.

Scotland has been drier this winter. The Scottish Environmental Protection Agency had a drought warning in place, especially for eastern and north-eastern areas, until rains in March brought much-needed moisture.

Simon Jones, director of conservation and visitor operations at Loch Lomond and The Trossachs National Park, said: “Sadly, over the years we’ve seen fires causing damage to some of the national park’s iconic landscapes such as Conic Hill and as recently as last weekend on the island of Inchcailloch, part of the Loch Lomond National Nature Reserve. It’s particularly at this time of year when the fire risk can be really high because dead vegetation and wood from last year is still lying on the ground. Warm, dry weather can then turn it into tinder which very easily catches fire.

“While campfires and barbecues can seem like a fun and innocent way to enjoy the outdoors, fires can get out of control and spread very quickly, causing devastating damage.

“Please help prevent wildfires this Easter. If you are in grassy or wooded areas of the National Park we strongly advise against having campfires and barbecues.”

The Met Office is predicting a predominantly fine, dry and settled bank holiday weekend for much of the UK, with the mercury hitting the high teens and low 20s on Saturday and Sunday in southern England.

Sonia Munde, head of services for Asthma UK, said: “A deadly pollen bomb is due to hit this week, putting people with asthma at risk of a potentially life-threatening asthma attack. Around 3.3 million people with asthma are affected by pollen, which can cause symptoms such as wheezing, a tight chest or coughing.

“Trees have been releasing their pollen for several weeks, but the warm spring weather is going to make these pollen levels spike.”

Discussing the ways that asthma sufferers can protect themselves, Ms Munde added: “If you’re already getting symptoms, it’s not too late to help yourself stay well.”