diff --git a/lambda/command.c b/lambda/command.c
index 59e7b9e..db53711 100644
--- a/lambda/command.c
+++ b/lambda/command.c
@@ -34,7 +34,7 @@
 }
 
 void runCommand(char* const data) {
-	uint8_t fieldCount = 8;
+	size_t fieldCount = 8;
 	char* fields[fieldCount];
 	split(data, " ", fields, fieldCount);
 	if (strcmp_P(fields[0], PSTR("se")) == 0) {
diff --git a/lambda/rules.h b/lambda/rules.h
index 3f97b01..f2f103f 100644
--- a/lambda/rules.h
+++ b/lambda/rules.h
@@ -40,9 +40,9 @@
  */
 #define TEMP_AIRGATE_0 450
 /** Temperature at which to consider the fire to have gone out */
-#define TEMP_FIRE_OUT 100
+#define TEMP_FIRE_OUT 90
 /** Min. temperature at which to consider the fire to fire up again */
-#define TEMP_FIRE_OUT_RESET 110
+#define TEMP_FIRE_OUT_RESET 100
 /** Max. lambda value that can be measured */
 #define LAMBDA_MAX 2000
 /** Combustion is considered too rich if lambda is below this value */
diff --git a/lambda/strings.c b/lambda/strings.c
index 4061040..1f67fba 100644
--- a/lambda/strings.c
+++ b/lambda/strings.c
@@ -11,8 +11,8 @@
 #include <string.h>
 
 void split(char* const string, char* const delim,
-		char* fields[], uint8_t const size) {
-	uint8_t index = 0;
+		char* fields[], size_t const size) {
+	size_t index = 0;
 	char* token = strtok(string, delim);
 	while (token != NULL && index < size) {
 		fields[index++] = token;