The vent openings 70 have a circular cross-sectional area and may have any diameter that facilitates air flow from the housing 64 through the top 36 of the cooling pad 34. For example, the diameter of the openings 70 may be in a range between about one-eighth (?) of an inch to about one inch. Additionally, any number of openings 70 may be provided that facilitates air to flow from the housing 64 through the top 36 of the cooling pad 34. For example, the number of openings 70 may range between about one and ten thousand.