This is a risky time in the vineyard as a severe frost can burn the buds. At worse this can result in the entire season's crop being lost. Whilst global warming is generally assisting viticulture in the UK, too much sunshine to early in spring means that the vines will be vulnerable to frost for longer.
Various attempts are often made to protect against frost including lighting oil heaters in the rows, spraying the vines with a chemical solution to form a seal around the buds, or even using helicopters to get air circulation. We can't use the chemicals or the helicopter as were organic so I guess I might be up tonight lighting oil lamps!