Purpose: Cell experiments are vitally dependent on CO2 incubators. The heating system of usual incubators result in undesirable induction of Electromagnetic (EM) fields on cells that result in decreased accuracy in bio-electromagnetic tests. EM shields can cause a considerable decrease in the stray fields and eliminate the undesirable induction. Materials and Methods: CST-2019 is used for simulations. five different shielding systems have been examined in this paper. We try to modify shape and material used for shielding to achieve better result. (Iron, Mu-Metal, steel). Results: We introduce a simple practical design, together with variations of previously reported ones, and numerical evaluation of their magnetic field attenuation. Conclusion: The targeted design decreases the field within the shield to about 0.03 times of the incident magnetic field, while having holes for air and CO2 exchange.