Stowaways in aircraft wheel wells face numerous health risks, many of which are fatal: being mangled when the undercarriage retracts, tinnitus, deafness, hypothermia, hypoxia, frostbite, acidosis and finally falling when the doors of the compartment reopen. The landing gear compartment is not equipped with heating, pressure or oxygen, which are vital for survival at a high altitude. According to experts, at , hypoxia causes lightheadedness, weakness, vision impairment and tremors. By the oxygen level of the blood drops and the person will struggle to stay conscious. Above their lungs would need artificial pressure to operate normally. The temperature could drop as low as which causes severe hypothermia. Those stowaways who managed to not be crushed by the retracting undercarriage or killed by the deadly conditions would most likely be unconscious when the compartment door re-opens during the approach and fall several thousand feet to their deaths.