Unseasonably wet and cold weather Friday resulted in fender benders, heavy snow and a rescue effort for schoolchildren who got cold on a Tuolumne County hike.

Medics treated four children after they suffered hypothermic symptoms while on a camping trip with their Napa Valley charter school in the Pinecrest Reservoir area, according to the Tuolumne County Sheriff's Department.

Sheriff's spokesman deputy Ken Diaz said the children were in triage at a fire station Friday afternoon.

He said 21 other children from Stone Bridge School were camping at Cleo's Bath near the reservoir. The other children were not sick and remained with their chaperones at the campsite.

Diaz said the children, along with school officials and two hiking guides, were out hiking Friday morning when the students began showing symptoms of hypothermia.

He said authorities used a boat to pick up the children and take them to the fire station.

The California Highway Patrol is advising drivers to behave "as you would if you were driving in December." Chains are required on Highway 108 east of Strawberry, and the California Department of Transportation closed Tioga Pass on Friday because of snow.

In Fresno, lightning knocked KSEE-TV off the air Friday morning.

Modesto reached a high of only 74 degrees Friday, and the Modesto Irrigation District recorded 0.14 inches of rain at its reservoir.

The unsettled conditions are expected to continue through the weekend and into next week, with snow in the higher elevations and a chance of showers in the valley. Highs around Modesto are expected to be back in the 80s, with lows in the 50s.