A limitation of using temperature as a surrogate measure of adherence is that in some climates, temperatures may exceed the reference temperature, and even body temperature at times. Local temperatures at clinical sites used in the ASPIRE and Ring Study clinical trials of the dapivirine IVR are typically not high enough to be above the 34.4°C reference temperature used in these adherence IVR studies. Average high temperatures during the summer months approach this limit in some areas of South Africa and Zimbabwe, and high temperatures for individual summer days may exceed the reference or body temperatures. Issues associated with high local temperatures can be mitigated to allow retrieval of usable adherence data even in cases where ambient temperatures exceed the reference temperature. An IVR that is removed and stored at ambient temperature will record diurnal temperature variations if the daily ambient high temperature exceeds the reference temperature. It would be rare for the low temperature, even on the hottest days, to be above a 34–35°C reference temperature. This diurnal pattern will be distinct, and can be correlated with historical temperature records or temperatures measured at clinical sites as part of a trial protocol.