Group 1 - High temperatures in closed car spaces can exceed 80℃, leading to potential explosions and fires from common items like lighters, perfumes, and power banks [1][5] - A simulation by firefighters showed that lighters can explode within 2 minutes at high temperatures due to the expansion of liquid butane [4][5] - Perfume bottles can eject their nozzles after 20 minutes in high heat, as alcohol inside vaporizes and increases pressure [4][6] Group 2 - Items like sunscreen and aerosol sprays can also explode in high temperatures due to increased internal pressure [6] - A magnifying glass can ignite paper within 40 minutes by focusing sunlight, similar to how other round objects can act as lenses [8] - Power banks can reach temperatures of 137℃ after 50 minutes in a hot car, posing risks of swelling and potential fires, especially if they contain substandard batteries [11] Group 3 - Cooling sprays can cause explosive reactions if used improperly near open flames, as demonstrated in a test where a fire ignited after spraying the product in a closed car [13] - Firefighters advise against leaving items like lighters, perfumes, and power banks in cars during summer to prevent accidents [13]