California’s wildfires are threatening to burn some of the state’s famous and gigantic groves of old-growth sequoias in Sierra Nevada, prompting officials to wrap them in aluminum foil insulation. Earlier this week, officials shared concerns that flames may continue to blaze through the area and reach the Giant Forest, and its grove of 2,000 trees, by Thursday, according to a briefing for fire crews. Firefighters took precautions by wrapping the base of the colossal General Sherman Tree and several other giant sequoias in fire-resistant aluminum foil that can withstand intense heat for short periods of time and reflect radiant heat. They also placed the metallic wrap on multiple buildings. The General Sherman Tree, which at 275 feet (83 m) tall, and over 36 feet (11 m) in diameter, is the largest known living single-stem tree on Earth. The tree is 2,300 to 2,700 years old. Giant sequoias are adapted to survive even the hottest of wildfires, which can help …