You are buried in a coffin 6ft deep, with no light or cell phone. There is only a small tube connected to the coffin from outside that allows you to breathe (edit: you can breathe with no difficulty). After 48 hours, you are dug up and given 1 million dollars. Do you do it?
Edit: No food and water, no diaper, and no contact with the outside world. Once buried, they leave for 48hr and come back to dig you up. The coffin is only wide enough for you to lay on your back (no rolling around), and the inside is wood and not particularly comfortable. The only items you’re allowed to bring with you are life sustaining medication (e.g. an asthma inhaler). No knocking yourself out with pills or anxiety meds. The money is a briefcase full of cash.
I imagine in a few hours that environment will be around body temperature.
You severely underestimate the heat storage capacity of the ground. Geothermal heat pumps work off that principle: at 6-8 feet underground the temperature is constant (in spite of the sun shining on it all the time, that should give you an idea how minimally one human body would impact it) and moving heat into it dissipates it in the ground and has a minimal impact. You probably wouldn’t even get a noticeable change in temperature in 48 hours. You can cool a whole house for a whole summer and probably only locally notice a 1° increase in local temperature around where it’s pumped to by the end of the summer, heat that then can be used in the winter.