Generally speaking, no, your body temperature will not increase simply because it is hot outside. The human body tends to use perspiration as a way to cool down. Some heat can be dispersed through respiration too, but that is minimal.
Conditions such as "heat stroke" usually occur in hot conditions combined with strenuous physical exertion, which forces the human body beyond its capacity to cool itself down.
Like one's pulse and blood pressure, temperature is also not a constant of the human body. 98.6 degrees is nothing more than an average temperature. Some individuals tend to run a little lower, and some higher.
Time of day is a factor. Upon waking, one's temperature is apt to be lower than any other time of the day. As an individual's day progresses, with greater activity, the body temperature will increase slightly.
Generally, our bodies do a great job of maintaining our vital signs.
The very best to you, Terri!... Chuck