Do not leave lithium batteries, pressurized gas containers, electronic chargers, food, or heat-sensitive protective equipment in a parked hot car. Take those items indoors or store them exactly as their manufacturers direct. A closed vehicle can heat rapidly even when the weather feels moderate, so the safest rule is to treat the car as transportation, not long-term storage.
Remove Lithium Batteries and Chargers
Lithium batteries store substantial energy and can overheat or ignite under fault conditions. The U.S. Pipeline and Hazardous Materials Safety Administration notes that lithium cells can present fire and electrical hazards and that damaged batteries have a greater potential to short circuit, release heat, or burn. PHMSA also identifies excessive heat as a condition associated with thermal runaway.
Remove batteries from the vehicle after transport. Keep terminals protected from metal objects, inspect packs for swelling, dents, damaged wiring, or unusual odor, and follow the battery and charger manufacturers' storage instructions. Do not use or charge a damaged pack. If a battery is swollen or otherwise suspect, move people away from the immediate hazard and follow local fire-safety and household hazardous-waste guidance rather than improvising a repair.
Chargers also belong indoors. A parked car is not a controlled charging area, and charging unattended is a poor safety practice. Use only compatible charging equipment and the procedure specified by the manufacturer.
Remove Pressurized Containers
Pressurized gas and aerosol-style containers should not remain in a hot vehicle. Heat raises pressure inside a sealed container, and product labels commonly direct users to avoid high temperatures and direct sunlight. Follow the exact label on the container; do not rely on a blanket temperature guessed from an online discussion.
A June 2026 r/airsoft thread about hot-car storage repeatedly warned against leaving batteries or gas cans in the vehicle. That is strong evidence that players encounter the question, but community comments are not a substitute for the container label or manufacturer instructions.
Protect Eye Gear and Electronics
Do not make the car the permanent home for goggles, masks, cameras, radios, or other electronics. Heat can stress adhesives, foams, seals, plastics, displays, and batteries. Store protective equipment clean and dry at normal indoor conditions, following its maker's instructions. Before the next game, inspect straps, frames, vents, and lenses; replace anything damaged or altered.
Keep prescription inserts and medications with you rather than in the vehicle. Also remove sunscreen and other products when their labels specify temperature limits.
Keep Food Out of the Heat
Perishable food should travel in a cooler, not sit loose in the trunk. The USDA says cold food should remain at 40°F or below and should be discarded after more than two hours unrefrigerated, or one hour when the air temperature is above 90°F. A hot vehicle is not safe food storage.
The National Weather Service documents how quickly parked vehicles can become dangerously hot. That rapid heating is enough reason to unload promptly after every trip. Make one final sweep for batteries, pressurized containers, electronics, protective gear, food, and living beings before locking the vehicle. A short unloading routine is far safer than trying to predict whether today's car temperature will stay below every item's limit.