Rave-goers suffered hypothermia after temperatures plummeted and it snowed at a techno festival .
Around 30 people were treated by medics at Teknival in France's Creuse region on Saturday.
But the mercury plunged to -3C and several centimetres of snow fell on the exposed, hilly site.
Organisers and the Red Cross handed out survival blankets but two people were dashed to hospital.
Photos show revellers huddled together and gathered around a small fire in desperate attempts to warm up.
Local media reports the festival was unauthorised, and that the French military - which owns the remote site - lodged an official complaint afterwards.
Temperatures in the region typically average at around 12C in May.
UK weather forecast: 800-MILE storm brings four days of washouts and flood fears
But violent storms - some wintry - have swept across France and Germany lately.
Some 10,000 people attended the 26th Teknival, an electronic music event.
The location changes each year and is only released at short notice.
Last year, local conservation groups alleged organisers disturbed a nature zone and unsettling the local birdlife.
It was held at another military base in northern France.
