The England Under-21 international has signed a one-month loan deal at Edgeley Park.
Heath is well down the pecking order at Leicester and Foxes boss Micky Adams is willing to loan him out so he can get valuable first team action.
McIlroy is keen to bolster his side's defence as they look to climb away from trouble at the wrong end of Division Two.
Heath could make his debut for The Hatters in this weekend's clash at Brighton.
