Just like a parked car with the windows up, the temperature in the Bubble Dome will always be many degrees hotter than the external temperature; therefore it will get hot in summer, maybe VERY hot. Keeping all the air vents open will help to reduce the heat inside. During sunny spring - summer days, when the outside temperature is above 50°F, the interior air temperature can rise to excessive heat levels (+140°F). These conditions may harm your Bubble Dome structure or any heat-sensitive furniture inside. Be especially observant of any plants or pets or small children. When the outside temperature is above 50°F, it is HIGHLY RECOMMENDED to monitor the interior temperature of the Bubble Dome, keeping the air vents open during the day time.