There are several possible causes.
A thermostat stuck open
A heater control valve stuck closed
A malfunctioning blend air door (located in the heater box)
Low coolant level
Malfunctioning heater controls
it could cause heat and excessive heat could affect the sperm production.
IT could be your ABS, auto control mech. or it could be something more serious.. I had this on my 06 Sedona and it turn out to be the regualator for the blund door of the ac unit The item was covered under the warrenty if that is still available for you Not a peep out of it now
a bad water pump could cause low heat. The heater uses the coolant from the pump to generate heat.
i have no heat in my 1994 mercury grand marquis. what could cause the heat to stop working
Heat!
The thermostat may be stuck open
Thermostat stuck open. Replace! A low coolant level will also cause this problem. The blend door could be stuck also.
There are a few things that can cause this, from heat stroke to heart attack. Even food poisoning could be the cause. Hard to know for sure.
Not quite sure of everything, but driving it in the heat for a long period of time could cause it to overheat.
dead battery
well it could be because of the heat. if its cold out and you have the heat on in the car, then you will get hot and that will cause the window to fog.
A possible cause could be that you have a clogged heater core.