CHABLIS, France (AP) — French vintners are lighting candles to thaw their grapevines to save them from a late frost following a winter warm spell, a temperature swing that is threatening fruit crops in multiple countries.

Ice-coated vines stretched across hillsides around Chablis as the Burgundy region woke Monday to temperatures of -5 C (23 F). Fruit growers are worried that the frost will kill off large numbers of early buds, which appeared in March as temperatures rose above 20 C (68 F), and disrupt the whole growing season.

The frost is particularly frustrating after a similar phenomenon hit French vineyards last year, leading to some 2 billion euros ($2.4 billion) in losses. Scientists later found that the damaging 2021 frost was made more likely by climate change.

Before dawn Monday, row upon row of candles flickered beneath the frosty vines in Chablis. As the sun rose, it illuminated the ice crystals gripping the vines.

While some vintners used candles, others tried to warm the vines with electrical lines, or sprayed the buds with water to protect them from frost.

In Switzerland, local media say the country’s crop of pitted fruits such as apricots, prunes and cherries is at risk from the icy spell.

The below-freezing temperatures are causing similar concerns about potential damage to apple and other fruit orchards in Belgium and the Netherlands.

Last year’s April frost led to what French government officials described as “probably the greatest agricultural catastrophe of the beginning of the 21st century.” The pattern was similar: an intense April 6-8 frost after a lengthy warm period in March.

Researchers with the group World Weather Attribution studied the effect of the 2021 frost on the vineyard-rich Champagne, Loire Valley and Burgundy regions of France, and found the March warmth made it particularly damaging.

The researchers concluded that the warming caused by man-made emissions had coaxed the plants into exposing their young leaves early, before a blast of Arctic cold reached Europe in April.