As of yet, no device can provide the best pressure relief; it only decreases the force exerted on the body's surface. Pressure sores may still only be avoided by physical therapy. Mattress climate is a critical factor in producing thermal comfort conditions when sleeping. This research examines a straightforward rubber mattress design with a thermoelectric air-cooling mechanism to lower the risk of pressure sores. The inlet cooling air temperature is maintained constant at 21 oC. The response of 10 volunteers lay awake on the mattress to the surface temperature at control room temperatures: switched on (25-26 oC) and switched off (29-30 oC) air conditioning system. It was found that thermoelectric air cooling significantly affects the mattress's temperature and moisture ventilation. Compared to mattresses without air conditioning, the temperature at different locations from the thermoelectric air-cooling box is lower, about 3-5 oC. The mattress temperature at the upper zone is the highest value, and the lower zone is the lowest. Therefore, to reduce the danger of pressure sores in the elderly and bedridden patients, this system could be a substitute for constructing a cooling mattress.