diff --git a/addons/medical/functions/fnc_handleUnitVitals.sqf b/addons/medical/functions/fnc_handleUnitVitals.sqf
index ebfb8be746..321f6dbd62 100644
--- a/addons/medical/functions/fnc_handleUnitVitals.sqf
+++ b/addons/medical/functions/fnc_handleUnitVitals.sqf
@@ -13,12 +13,15 @@
 
 #include "script_component.hpp"
 
-private ["_unit", "_heartRate","_bloodPressure","_bloodVolume","_painStatus", "_lastTimeValuesSynced", "_syncValues", "_airwayStatus", "_blood", "_bloodPressureH", "_bloodPressureL", "_interval"];
+private ["_unit", "_heartRate","_bloodPressure","_bloodVolume","_painStatus", "_lastTimeValuesSynced", "_syncValues", "_airwayStatus", "_blood", "_bloodPressureH", "_bloodPressureL", "_interval", "_lastMomentVitalsHandled"];
 _unit = _this select 0;
 
-_interval = time - (_unit getVariable [QGVAR(lastMomentVitalsHandled), 0]);
+_lastMomentVitalsHandled = _unit getVariable [QGVAR(lastMomentVitalsHandled), -1];
 _unit setVariable [QGVAR(lastMomentVitalsHandled), time];
 
+//If QGVAR(lastMomentVitalsHandled) is undefined then assume 1 second interval:
+_interval = if (_lastMomentVitalsHandled == -1) then {1} else {time - _lastMomentVitalsHandled};
+
 if (_interval == 0) exitWith {};
 
 _lastTimeValuesSynced = _unit getvariable [QGVAR(lastMomentValuesSynced), 0];